56621551 has 8 divisors (see below), whose sum is σ = 64871840. Its totient is φ = 48411648.

The previous prime is 56621491. The next prime is 56621557. The reversal of 56621551 is 15512665.

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 56621551 - 2⁹ = 56621039 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56621557) 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, 7026 + ... + 12751.

It is an arithmetic number, because the mean of its divisors is an integer number (8108980).

Almost surely, 2^56621551 is an apocalyptic number.

56621551 is a deficient number, since it is larger than the sum of its proper divisors (8250289).

56621551 is a wasteful number, since it uses less digits than its factorization.

56621551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20193.

The product of its digits is 9000, while the sum is 31.

The square root of 56621551 is about 7524.7292974565. The cubic root of 56621551 is about 383.9964893161.

The spelling of 56621551 in words is "fifty-six million, six hundred twenty-one thousand, five hundred fifty-one".