64797781693680 has 240 divisors, whose sum is σ = 248708330380224. Its totient is φ = 14810428846080.

The previous prime is 64797781693657. The next prime is 64797781693691. The reversal of 64797781693680 is 8639618779746.

64797781693680 is a `hidden beast` number, since 6 + 4 + 7 + 97 + 7 + 8 + 169 + 368 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a self number, because there is not a number n which added to its sum of digits gives 64797781693680.

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, 163788910 + ... + 164184050.

Almost surely, 2^{64797781693680} is an apocalyptic number.

64797781693680 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

64797781693680 is an abundant number, since it is smaller than the sum of its proper divisors (183910548686544).

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

64797781693680 is a wasteful number, since it uses less digits than its factorization.

64797781693680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427704 (or 427695 counting only the distinct ones).

The product of its (nonzero) digits is 4608866304, while the sum is 81.

The spelling of 64797781693680 in words is "sixty-four trillion, seven hundred ninety-seven billion, seven hundred eighty-one million, six hundred ninety-three thousand, six hundred eighty".