65557620864 has 192 divisors, whose sum is σ = 202384728000. Its totient is φ = 21098714112.

The previous prime is 65557620841. The next prime is 65557620901. The reversal of 65557620864 is 46802675556.

65557620864 is a `hidden beast` number, since 6 + 5 + 5 + 5 + 7 + 620 + 8 + 6 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 65557620864.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 865677 + ... + 938355.

It is an arithmetic number, because the mean of its divisors is an integer number (1054087125).

Almost surely, 2^65557620864 is an apocalyptic number.

65557620864 is a gapful number since it is divisible by the number (64) 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 65557620864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101192364000).

65557620864 is an abundant number, since it is smaller than the sum of its proper divisors (136827107136).

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

65557620864 is an equidigital number, since it uses as much as digits as its factorization.

65557620864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72737 (or 72713 counting only the distinct ones).

The product of its (nonzero) digits is 12096000, while the sum is 54.

The spelling of 65557620864 in words is "sixty-five billion, five hundred fifty-seven million, six hundred twenty thousand, eight hundred sixty-four".