77670891 has 12 divisors (see below), whose sum is σ = 112307832. Its totient is φ = 51726816.

The previous prime is 77670871. The next prime is 77670899. The reversal of 77670891 is 19807677.

It is a happy number.

It is not a de Polignac number, because 77670891 - 2⁷ = 77670763 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77670899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5940 + ... + 13806.

It is an arithmetic number, because the mean of its divisors is an integer number (9358986).

Almost surely, 2^77670891 is an apocalyptic number.

77670891 is a deficient number, since it is larger than the sum of its proper divisors (34636941).

77670891 is a wasteful number, since it uses less digits than its factorization.

77670891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8970 (or 8967 counting only the distinct ones).

The product of its (nonzero) digits is 148176, while the sum is 45.

The square root of 77670891 is about 8813.1090427839. The cubic root of 77670891 is about 426.6640934768.

The spelling of 77670891 in words is "seventy-seven million, six hundred seventy thousand, eight hundred ninety-one".