1291830212221 has 8 divisors (see below), whose sum is σ = 1310866943544. Its totient is φ = 1272829708800.

The previous prime is 1291830212213. The next prime is 1291830212227. The reversal of 1291830212221 is 1222120381921.

It can be written as a sum of positive squares in 4 ways, for example, as 778012202500 + 513818009721 = 882050^2 + 716811^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1291830212221 - 2³ = 1291830212213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291830212227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8985130 + ... + 9127771.

It is an arithmetic number, because the mean of its divisors is an integer number (163858367943).

Almost surely, 2^{1291830212221} is an apocalyptic number.

It is an amenable number.

1291830212221 is a deficient number, since it is larger than the sum of its proper divisors (19036731323).

1291830212221 is an equidigital number, since it uses as much as digits as its factorization.

1291830212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18113951.

The product of its (nonzero) digits is 6912, while the sum is 34.

It can be divided in two parts, 1291830 and 212221, that added together give a palindrome (1504051).

The spelling of 1291830212221 in words is "one trillion, two hundred ninety-one billion, eight hundred thirty million, two hundred twelve thousand, two hundred twenty-one".