78518978 has 16 divisors (see below), whose sum is σ = 119445144. Its totient is φ = 38707200.

The previous prime is 78518959. The next prime is 78518983. The reversal of 78518978 is 87981587.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 29560969 + 48958009 = 5437^2 + 6997^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64778 + ... + 65978.

Almost surely, 2^78518978 is an apocalyptic number.

78518978 is a deficient number, since it is larger than the sum of its proper divisors (40926166).

78518978 is a wasteful number, since it uses less digits than its factorization.

78518978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1637.

The product of its digits is 1128960, while the sum is 53.

The square root of 78518978 is about 8861.0934991117. The cubic root of 78518978 is about 428.2113878491.

The spelling of 78518978 in words is "seventy-eight million, five hundred eighteen thousand, nine hundred seventy-eight".