77868891 has 16 divisors (see below), whose sum is σ = 122148000. Its totient is φ = 48858624.

The previous prime is 77868887. The next prime is 77868911. The reversal of 77868891 is 19886877.

It is not a de Polignac number, because 77868891 - 2² = 77868887 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77868841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 84366 + ... + 85283.

It is an arithmetic number, because the mean of its divisors is an integer number (7634250).

Almost surely, 2^77868891 is an apocalyptic number.

77868891 is a deficient number, since it is larger than the sum of its proper divisors (44279109).

77868891 is a wasteful number, since it uses less digits than its factorization.

77868891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169675 (or 169669 counting only the distinct ones).

The product of its digits is 1354752, while the sum is 54.

The square root of 77868891 is about 8824.3351590927. The cubic root of 77868891 is about 427.0263390378.

The spelling of 77868891 in words is "seventy-seven million, eight hundred sixty-eight thousand, eight hundred ninety-one".