1055921521 has 4 divisors (see below), whose sum is σ = 1057491172. Its totient is φ = 1054351872.

The previous prime is 1055921509. The next prime is 1055921539. The reversal of 1055921521 is 1251295501.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 691111521 + 364810000 = 26289^2 + 19100^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1055921521 is a prime.

It is a super-2 number, since 2×1055921521² = 2229940517021906882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1055921551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 783816 + ... + 785161.

It is an arithmetic number, because the mean of its divisors is an integer number (264372793).

Almost surely, 2^1055921521 is an apocalyptic number.

It is an amenable number.

1055921521 is a deficient number, since it is larger than the sum of its proper divisors (1569651).

1055921521 is an equidigital number, since it uses as much as digits as its factorization.

1055921521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1569650.

The product of its (nonzero) digits is 4500, while the sum is 31.

The square root of 1055921521 is about 32494.9460839682. The cubic root of 1055921521 is about 1018.3034468499.

The spelling of 1055921521 in words is "one billion, fifty-five million, nine hundred twenty-one thousand, five hundred twenty-one".