78699618 has 12 divisors (see below), whose sum is σ = 170515878. Its totient is φ = 26233200.

The previous prime is 78699601. The next prime is 78699619. The reversal of 78699618 is 81699687.

It can be written as a sum of positive squares in only one way, i.e., 58476609 + 20223009 = 7647^2 + 4497^2 .

It is not an unprimeable number, because it can be changed into a prime (78699619) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2186083 + ... + 2186118.

Almost surely, 2^78699618 is an apocalyptic number.

78699618 is an abundant number, since it is smaller than the sum of its proper divisors (91816260).

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

78699618 is a wasteful number, since it uses less digits than its factorization.

78699618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4372209 (or 4372206 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 54.

The square root of 78699618 is about 8871.2805163629. The cubic root of 78699618 is about 428.5395160047.

The spelling of 78699618 in words is "seventy-eight million, six hundred ninety-nine thousand, six hundred eighteen".