1056216421 has 8 divisors (see below), whose sum is σ = 1141056504. Its totient is φ = 971889600.

The previous prime is 1056216389. The next prime is 1056216463. The reversal of 1056216421 is 1246126501.

It can be written as a sum of positive squares in 4 ways, for example, as 25100100 + 1031116321 = 5010^2 + 32111^2 .

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 1056216421 - 2⁵ = 1056216389 is a prime.

It is a super-2 number, since 2×1056216421² = 2231186255980098482, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1056216421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1056216121) 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, 124030 + ... + 132271.

It is an arithmetic number, because the mean of its divisors is an integer number (142632063).

Almost surely, 2^1056216421 is an apocalyptic number.

It is an amenable number.

1056216421 is a deficient number, since it is larger than the sum of its proper divisors (84840083).

1056216421 is a wasteful number, since it uses less digits than its factorization.

1056216421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256631.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 1056216421 is about 32499.4833958942. The cubic root of 1056216421 is about 1018.3982360076.

The spelling of 1056216421 in words is "one billion, fifty-six million, two hundred sixteen thousand, four hundred twenty-one".