64649646720 has 128 divisors (see below), whose sum is σ = 228967560000. Its totient is φ = 17239901184.

The previous prime is 64649646709. The next prime is 64649646739. The reversal of 64649646720 is 2764694646.

It is a happy number.

64649646720 is a `hidden beast` number, since 6 + 46 + 496 + 46 + 72 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (128).

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

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, 1853370 + ... + 1887929.

Almost surely, 2^64649646720 is an apocalyptic number.

64649646720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

64649646720 is an abundant number, since it is smaller than the sum of its proper divisors (164317913280).

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

64649646720 is a wasteful number, since it uses less digits than its factorization.

64649646720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3741327 (or 3741309 counting only the distinct ones).

The product of its (nonzero) digits is 10450944, while the sum is 54.

The spelling of 64649646720 in words is "sixty-four billion, six hundred forty-nine million, six hundred forty-six thousand, seven hundred twenty".