66656040 has 64 divisors (see below), whose sum is σ = 218151360. Its totient is φ = 16158720.

The previous prime is 66656039. The next prime is 66656041. The reversal of 66656040 is 4065666.

It is an interprime number because it is at equal distance from previous prime (66656039) and next prime (66656041).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 66655992 and 66656010.

It is not an unprimeable number, because it can be changed into a prime (66656041) 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, 23929 + ... + 26568.

It is an arithmetic number, because the mean of its divisors is an integer number (3408615).

Almost surely, 2^66656040 is an apocalyptic number.

66656040 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66656040 is an abundant number, since it is smaller than the sum of its proper divisors (151495320).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66656040 is a wasteful number, since it uses less digits than its factorization.

66656040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50522 (or 50518 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 33.

The square root of 66656040 is about 8164.3150355679. The cubic root of 66656040 is about 405.4585873823.

The spelling of 66656040 in words is "sixty-six million, six hundred fifty-six thousand, forty".