78728564 has 12 divisors (see below), whose sum is σ = 145879524. Its totient is φ = 37048704.

The previous prime is 78728549. The next prime is 78728593. The reversal of 78728564 is 46582787.

It can be written as a sum of positive squares in 2 ways, for example, as 66422500 + 12306064 = 8150^2 + 3508^2 .

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 578819 + ... + 578954.

It is an arithmetic number, because the mean of its divisors is an integer number (12156627).

Almost surely, 2^78728564 is an apocalyptic number.

It is an amenable number.

78728564 is a deficient number, since it is larger than the sum of its proper divisors (67150960).

78728564 is a wasteful number, since it uses less digits than its factorization.

78728564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1157794 (or 1157792 counting only the distinct ones).

The product of its digits is 752640, while the sum is 47.

The square root of 78728564 is about 8872.9118106741. The cubic root of 78728564 is about 428.5920490184.

The spelling of 78728564 in words is "seventy-eight million, seven hundred twenty-eight thousand, five hundred sixty-four".