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1321212121221 = 3440404040407
BaseRepresentation
bin10011001110011110011…
…000010001000010000101
311200022021112200212012110
4103032132120101002011
5133121320300334341
62450542333011233
7164311603506366
oct23163630210205
94608245625173
101321212121221
1146a360886893
12194087323b19
139778894b765
1447d38837b6d
152457b2c3216
hex1339e611085

1321212121221 has 4 divisors (see below), whose sum is σ = 1761616161632. Its totient is φ = 880808080812.

The previous prime is 1321212121199. The next prime is 1321212121267. The reversal of 1321212121221 is 1221212121231.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1321212121221 - 211 = 1321212119173 is a prime.

It is a super-2 number, since 2×13212121212212 (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321212122221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 220202020201 + ... + 220202020206.

It is an arithmetic number, because the mean of its divisors is an integer number (440404040408).

Almost surely, 21321212121221 is an apocalyptic number.

It is an amenable number.

1321212121221 is a deficient number, since it is larger than the sum of its proper divisors (440404040411).

1321212121221 is an equidigital number, since it uses as much as digits as its factorization.

1321212121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440404040410.

The product of its digits is 192, while the sum is 21.

Adding to 1321212121221 its reverse (1221212121231), we get a palindrome (2542424242452).

The spelling of 1321212121221 in words is "one trillion, three hundred twenty-one billion, two hundred twelve million, one hundred twenty-one thousand, two hundred twenty-one".

Divisors: 1 3 440404040407 1321212121221