1056311521 has 4 divisors (see below), whose sum is σ = 1059644052. Its totient is φ = 1052978992.

The previous prime is 1056311491. The next prime is 1056311537. The reversal of 1056311521 is 1251136501.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1251136501 = 6827 ⋅183263.

It can be written as a sum of positive squares in 2 ways, for example, as 298080225 + 758231296 = 17265^2 + 27536^2 .

It is a cyclic number.

It is not a de Polignac number, because 1056311521 - 2¹³ = 1056303329 is a prime.

It is a super-2 number, since 2×1056311521² = 2231588058794666882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1056311551) 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, 1665790 + ... + 1666423.

It is an arithmetic number, because the mean of its divisors is an integer number (264911013).

Almost surely, 2^1056311521 is an apocalyptic number.

It is an amenable number.

1056311521 is a deficient number, since it is larger than the sum of its proper divisors (3332531).

1056311521 is an equidigital number, since it uses as much as digits as its factorization.

1056311521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3332530.

The product of its (nonzero) digits is 900, while the sum is 25.

The square root of 1056311521 is about 32500.9464631417. The cubic root of 1056311521 is about 1018.4288000612.

The spelling of 1056311521 in words is "one billion, fifty-six million, three hundred eleven thousand, five hundred twenty-one".