72818978 has 4 divisors (see below), whose sum is σ = 109228470. Its totient is φ = 36409488.

The previous prime is 72818959. The next prime is 72818981. The reversal of 72818978 is 87981827.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 72812089 + 6889 = 8533^2 + 83^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18204743 + ... + 18204746.

Almost surely, 2^72818978 is an apocalyptic number.

72818978 is a deficient number, since it is larger than the sum of its proper divisors (36409492).

72818978 is a wasteful number, since it uses less digits than its factorization.

72818978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36409491.

The product of its digits is 451584, while the sum is 50.

The square root of 72818978 is about 8533.4036585644. The cubic root of 72818978 is about 417.5881760046.

The spelling of 72818978 in words is "seventy-two million, eight hundred eighteen thousand, nine hundred seventy-eight".