65663640 has 192 divisors, whose sum is σ = 248002560. Its totient is φ = 14757120.

The previous prime is 65663603. The next prime is 65663651. The reversal of 65663640 is 4636656.

65663640 is a `hidden beast` number, since 6 + 5 + 6 + 6 + 3 + 640 = 666.

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 = 65663595 and 65663604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 178737 + ... + 179103.

It is an arithmetic number, because the mean of its divisors is an integer number (1291680).

Almost surely, 2^65663640 is an apocalyptic number.

65663640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 65663640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124001280).

65663640 is an abundant number, since it is smaller than the sum of its proper divisors (182338920).

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

65663640 is a wasteful number, since it uses less digits than its factorization.

65663640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 462 (or 455 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 36.

The square root of 65663640 is about 8103.3104346310. The cubic root of 65663640 is about 403.4363115392.

The spelling of 65663640 in words is "sixty-five million, six hundred sixty-three thousand, six hundred forty".