56665638 has 48 divisors (see below), whose sum is σ = 129991680. Its totient is φ = 17790192.

The previous prime is 56665633. The next prime is 56665663. The reversal of 56665638 is 83656665.

It is a junction number, because it is equal to n+sod(n) for n = 56665593 and 56665602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56665633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 75895 + ... + 76637.

It is an arithmetic number, because the mean of its divisors is an integer number (2708160).

Almost surely, 2^56665638 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 56665638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (64995840).

56665638 is an abundant number, since it is smaller than the sum of its proper divisors (73326042).

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

56665638 is a wasteful number, since it uses less digits than its factorization.

56665638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 993 (or 990 counting only the distinct ones).

The product of its digits is 777600, while the sum is 45.

The square root of 56665638 is about 7527.6582015923. The cubic root of 56665638 is about 384.0961266508.

The spelling of 56665638 in words is "fifty-six million, six hundred sixty-five thousand, six hundred thirty-eight".