78561618 has 32 divisors (see below), whose sum is σ = 166272000. Its totient is φ = 24677136.

The previous prime is 78561589. The next prime is 78561653. The reversal of 78561618 is 81616587.

It is an alternating number because its digits alternate between odd and even.

It is a self number, because there is not a number n which added to its sum of digits gives 78561618.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20955 + ... + 24417.

It is an arithmetic number, because the mean of its divisors is an integer number (5196000).

Almost surely, 2^78561618 is an apocalyptic number.

78561618 is an abundant number, since it is smaller than the sum of its proper divisors (87710382).

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

78561618 is a wasteful number, since it uses less digits than its factorization.

78561618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3686.

The product of its digits is 80640, while the sum is 42.

The square root of 78561618 is about 8863.4991961414. The cubic root of 78561618 is about 428.2888877090.

The spelling of 78561618 in words is "seventy-eight million, five hundred sixty-one thousand, six hundred eighteen".