77681618 has 16 divisors (see below), whose sum is σ = 133284480. Its totient is φ = 33263136.

The previous prime is 77681579. The next prime is 77681641. The reversal of 77681618 is 81618677.

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, 24830 + ... + 27782.

It is an arithmetic number, because the mean of its divisors is an integer number (8330280).

Almost surely, 2^77681618 is an apocalyptic number.

77681618 is a deficient number, since it is larger than the sum of its proper divisors (55602862).

77681618 is a wasteful number, since it uses less digits than its factorization.

77681618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4841.

The product of its digits is 112896, while the sum is 44.

The square root of 77681618 is about 8813.7176038264. The cubic root of 77681618 is about 426.6837345332.

The spelling of 77681618 in words is "seventy-seven million, six hundred eighty-one thousand, six hundred eighteen".