78378728 has 16 divisors (see below), whose sum is σ = 150932580. Its totient is φ = 38130048.

The previous prime is 78378709. The next prime is 78378731. The reversal of 78378728 is 82787387.

It can be written as a sum of positive squares in 2 ways, for example, as 63648484 + 14730244 = 7978^2 + 3838^2 .

It is a super-2 number, since 2×78378728² = 12286450005795968, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 132101 + ... + 132692.

Almost surely, 2^78378728 is an apocalyptic number.

It is an amenable number.

78378728 is a deficient number, since it is larger than the sum of its proper divisors (72553852).

78378728 is a wasteful number, since it uses less digits than its factorization.

78378728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264836 (or 264832 counting only the distinct ones).

The product of its digits is 1053696, while the sum is 50.

The square root of 78378728 is about 8853.1761532232. The cubic root of 78378728 is about 427.9562799258.

The spelling of 78378728 in words is "seventy-eight million, three hundred seventy-eight thousand, seven hundred twenty-eight".