56442640 has 20 divisors (see below), whose sum is σ = 131229324. Its totient is φ = 22577024.

The previous prime is 56442623. The next prime is 56442647. The reversal of 56442640 is 4624465.

It can be written as a sum of positive squares in 2 ways, for example, as 10419984 + 46022656 = 3228^2 + 6784^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×56442640² = 6371543220339200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (56442647) 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, 352687 + ... + 352846.

Almost surely, 2^56442640 is an apocalyptic number.

It is an amenable number.

56442640 is an abundant number, since it is smaller than the sum of its proper divisors (74786684).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

56442640 is a wasteful number, since it uses less digits than its factorization.

56442640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 705546 (or 705540 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 31.

The square root of 56442640 is about 7512.8316898490. The cubic root of 56442640 is about 383.5916158952.

The spelling of 56442640 in words is "fifty-six million, four hundred forty-two thousand, six hundred forty".