64425617657856 has 1664 divisors, whose sum is σ = 251857130112000. Its totient is φ = 15988439384064.

The previous prime is 64425617657833. The next prime is 64425617657897. The reversal of 64425617657856 is 65875671652446.

64425617657856 is a `hidden beast` number, since 6 + 4 + 4 + 2 + 561 + 7 + 6 + 5 + 7 + 8 + 56 = 666.

It is a tau number, because it is divible by the number of its divisors (1664).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 13857949420 + ... + 13857954068.

Almost surely, 2^{64425617657856} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64425617657856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125928565056000).

64425617657856 is an abundant number, since it is smaller than the sum of its proper divisors (187431512454144).

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

64425617657856 is an equidigital number, since it uses as much as digits as its factorization.

64425617657856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4731 (or 4691 counting only the distinct ones).

The product of its digits is 2032128000, while the sum is 72.

The spelling of 64425617657856 in words is "sixty-four trillion, four hundred twenty-five billion, six hundred seventeen million, six hundred fifty-seven thousand, eight hundred fifty-six".