65656440 has 64 divisors (see below), whose sum is σ = 218858400. Its totient is φ = 17508096.

The previous prime is 65656427. The next prime is 65656489. The reversal of 65656440 is 4465656.

It is a happy number.

65656440 is a `hidden beast` number, since 6 + 5 + 6 + 5 + 644 + 0 = 666.

It is a super-2 number, since 2×65656440² = 8621536226947200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 65656395 and 65656404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29317 + ... + 31476.

Almost surely, 2^65656440 is an apocalyptic number.

65656440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

65656440 is an abundant number, since it is smaller than the sum of its proper divisors (153201960).

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

65656440 is a wasteful number, since it uses less digits than its factorization.

65656440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60813 (or 60803 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 36.

The square root of 65656440 is about 8102.8661595759. The cubic root of 65656440 is about 403.4215654402.

The spelling of 65656440 in words is "sixty-five million, six hundred fifty-six thousand, four hundred forty".