77681668 has 12 divisors (see below), whose sum is σ = 137858112. Its totient is φ = 38293640.

The previous prime is 77681663. The next prime is 77681683. The reversal of 77681668 is 86618677.

It is not an unprimeable number, because it can be changed into a prime (77681663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136480 + ... + 137047.

It is an arithmetic number, because the mean of its divisors is an integer number (11488176).

Almost surely, 2^77681668 is an apocalyptic number.

It is an amenable number.

77681668 is a deficient number, since it is larger than the sum of its proper divisors (60176444).

77681668 is a wasteful number, since it uses less digits than its factorization.

77681668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273602 (or 273600 counting only the distinct ones).

The product of its digits is 677376, while the sum is 49.

The square root of 77681668 is about 8813.7204403135. The cubic root of 77681668 is about 426.6838260785.

The spelling of 77681668 in words is "seventy-seven million, six hundred eighty-one thousand, six hundred sixty-eight".