56660021 has 8 divisors (see below), whose sum is σ = 62977824. Its totient is φ = 50536720.

The previous prime is 56660011. The next prime is 56660039. The reversal of 56660021 is 12006665.

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 56660021 - 2¹⁸ = 56397877 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56660011) 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, 48011 + ... + 49176.

It is an arithmetic number, because the mean of its divisors is an integer number (7872228).

Almost surely, 2^56660021 is an apocalyptic number.

It is an amenable number.

56660021 is a deficient number, since it is larger than the sum of its proper divisors (6317803).

56660021 is a wasteful number, since it uses less digits than its factorization.

56660021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97251.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 56660021 is about 7527.2851015489. The cubic root of 56660021 is about 384.0834350131.

Adding to 56660021 its reverse (12006665), we get a palindrome (68666686).

The spelling of 56660021 in words is "fifty-six million, six hundred sixty thousand, twenty-one".