64978544736 has 120 divisors (see below), whose sum is σ = 218400169680. Its totient is φ = 18565293312.

The previous prime is 64978544711. The next prime is 64978544747. The reversal of 64978544736 is 63744587946.

It is a happy number.

64978544736 is a `hidden beast` number, since 6 + 49 + 78 + 54 + 473 + 6 = 666.

It is a super-2 number, since 2×64978544736² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1772491 + ... + 1808778.

It is an arithmetic number, because the mean of its divisors is an integer number (1820001414).

Almost surely, 2^64978544736 is an apocalyptic number.

It is an amenable number.

64978544736 is an abundant number, since it is smaller than the sum of its proper divisors (153421624944).

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

64978544736 is a wasteful number, since it uses less digits than its factorization.

64978544736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3581298 (or 3581281 counting only the distinct ones).

The product of its digits is 121927680, while the sum is 63.

The spelling of 64978544736 in words is "sixty-four billion, nine hundred seventy-eight million, five hundred forty-four thousand, seven hundred thirty-six".