813405987 has 12 divisors (see below), whose sum is σ = 1244032920. Its totient is φ = 510372288.

The previous prime is 813405973. The next prime is 813405997. The reversal of 813405987 is 789504318.

813405987 is a `hidden beast` number, since 8 + 13 + 40 + 598 + 7 = 666.

It is not a de Polignac number, because 813405987 - 2²⁰ = 812357411 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (813405997) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2658037 + ... + 2658342.

It is an arithmetic number, because the mean of its divisors is an integer number (103669410).

Almost surely, 2^813405987 is an apocalyptic number.

813405987 is a deficient number, since it is larger than the sum of its proper divisors (430626933).

813405987 is a wasteful number, since it uses less digits than its factorization.

813405987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5316402 (or 5316399 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The square root of 813405987 is about 28520.2732630667. The cubic root of 813405987 is about 933.4744918160.

The spelling of 813405987 in words is "eight hundred thirteen million, four hundred five thousand, nine hundred eighty-seven".