813900987 has 16 divisors (see below), whose sum is σ = 1209595680. Its totient is φ = 540883296.

The previous prime is 813900961. The next prime is 813901051. The reversal of 813900987 is 789009318.

It is not a de Polignac number, because 813900987 - 2⁷ = 813900859 is a prime.

It is not an unprimeable number, because it can be changed into a prime (813900917) 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 15 ways as a sum of consecutive naturals, for example, 38988 + ... + 56105.

It is an arithmetic number, because the mean of its divisors is an integer number (75599730).

Almost surely, 2^813900987 is an apocalyptic number.

813900987 is a deficient number, since it is larger than the sum of its proper divisors (395694693).

813900987 is a wasteful number, since it uses less digits than its factorization.

813900987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95419 (or 95413 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 45.

The square root of 813900987 is about 28528.9499806775. The cubic root of 813900987 is about 933.6638094021.

The spelling of 813900987 in words is "eight hundred thirteen million, nine hundred thousand, nine hundred eighty-seven".