56421561 has 24 divisors (see below), whose sum is σ = 87320640. Its totient is φ = 31741632.

The previous prime is 56421557. The next prime is 56421577. The reversal of 56421561 is 16512465.

It is not a de Polignac number, because 56421561 - 2² = 56421557 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (56421161) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 359295 + ... + 359451.

It is an arithmetic number, because the mean of its divisors is an integer number (3638360).

Almost surely, 2^56421561 is an apocalyptic number.

It is an amenable number.

56421561 is a deficient number, since it is larger than the sum of its proper divisors (30899079).

56421561 is a wasteful number, since it uses less digits than its factorization.

56421561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433 (or 276 counting only the distinct ones).

The product of its digits is 7200, while the sum is 30.

The square root of 56421561 is about 7511.4286923328. The cubic root of 56421561 is about 383.5438580627.

The spelling of 56421561 in words is "fifty-six million, four hundred twenty-one thousand, five hundred sixty-one".