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1221330257 = 7174475751
BaseRepresentation
bin100100011001100…
…0000010101010001
310011010011000010222
41020303000111101
510000130032012
6321105202425
742160064420
oct11063002521
93133130128
101221330257
11577455554
122a1030415
13166052234
14b82c32b7
1572350972
hex48cc0551

1221330257 has 4 divisors (see below), whose sum is σ = 1395806016. Its totient is φ = 1046854500.

The previous prime is 1221330217. The next prime is 1221330259. The reversal of 1221330257 is 7520331221.

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, and also an emirpimes, since its reverse is a distinct semiprime: 7520331221 = 13578487017.

It is a cyclic number.

It is not a de Polignac number, because 1221330257 - 228 = 952894801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221330259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 87237869 + ... + 87237882.

It is an arithmetic number, because the mean of its divisors is an integer number (348951504).

Almost surely, 21221330257 is an apocalyptic number.

It is an amenable number.

1221330257 is a deficient number, since it is larger than the sum of its proper divisors (174475759).

1221330257 is an equidigital number, since it uses as much as digits as its factorization.

1221330257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174475758.

The product of its (nonzero) digits is 2520, while the sum is 26.

The square root of 1221330257 is about 34947.5357786497. The cubic root of 1221330257 is about 1068.9179549684.

Adding to 1221330257 its reverse (7520331221), we get a palindrome (8741661478).

The spelling of 1221330257 in words is "one billion, two hundred twenty-one million, three hundred thirty thousand, two hundred fifty-seven".

Divisors: 1 7 174475751 1221330257