64677777720 has 64 divisors (see below), whose sum is σ = 205447065120. Its totient is φ = 16232853504.

The previous prime is 64677777707. The next prime is 64677777721. The reversal of 64677777720 is 2777777646.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64677777721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15850357 + ... + 15854436.

Almost surely, 2^64677777720 is an apocalyptic number.

64677777720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

64677777720 is an abundant number, since it is smaller than the sum of its proper divisors (140769287400).

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

64677777720 is a wasteful number, since it uses less digits than its factorization.

64677777720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31704824 (or 31704820 counting only the distinct ones).

The product of its (nonzero) digits is 33882912, while the sum is 60.

The spelling of 64677777720 in words is "sixty-four billion, six hundred seventy-seven million, seven hundred seventy-seven thousand, seven hundred twenty".