56666555 has 16 divisors (see below), whose sum is σ = 74923488. Its totient is φ = 40804000.

The previous prime is 56666509. The next prime is 56666557. The reversal of 56666555 is 55566665.

It is a de Polignac number, because none of the positive numbers 2^k-56666555 is a prime.

It is a super-2 number, since 2×56666555² = 6422196911136050, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (56666557) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 561005 + ... + 561105.

It is an arithmetic number, because the mean of its divisors is an integer number (4682718).

Almost surely, 2^56666555 is an apocalyptic number.

56666555 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

56666555 is a deficient number, since it is larger than the sum of its proper divisors (18256933).

56666555 is an frugal number, since it uses more digits than its factorization.

56666555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 319 (or 117 counting only the distinct ones).

The product of its digits is 810000, while the sum is 44.

The square root of 56666555 is about 7527.7191100625. The cubic root of 56666555 is about 384.0981985369.

It can be divided in two parts, 5666 and 6555, that added together give a palindrome (12221).

The spelling of 56666555 in words is "fifty-six million, six hundred sixty-six thousand, five hundred fifty-five".