56553981 has 16 divisors (see below), whose sum is σ = 82555200. Its totient is φ = 34152320.

The previous prime is 56553979. The next prime is 56553997. The reversal of 56553981 is 18935565.

It is a cyclic number.

It is not a de Polignac number, because 56553981 - 2¹ = 56553979 is a prime.

It is a super-2 number, since 2×56553981² = 6396705533896722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56553911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6745 + ... + 12593.

It is an arithmetic number, because the mean of its divisors is an integer number (5159700).

Almost surely, 2^56553981 is an apocalyptic number.

It is an amenable number.

56553981 is a deficient number, since it is larger than the sum of its proper divisors (26001219).

56553981 is a wasteful number, since it uses less digits than its factorization.

56553981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6156.

The product of its digits is 162000, while the sum is 42.

The square root of 56553981 is about 7520.2380946350. The cubic root of 56553981 is about 383.8436795914.

The spelling of 56553981 in words is "fifty-six million, five hundred fifty-three thousand, nine hundred eighty-one".