813887 has 4 divisors (see below), whose sum is σ = 816816. Its totient is φ = 810960.

The previous prime is 813871. The next prime is 813893. The reversal of 813887 is 788318.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 813887 - 2⁴ = 813871 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (813817) 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 3 ways as a sum of consecutive naturals, for example, 998 + ... + 1619.

It is an arithmetic number, because the mean of its divisors is an integer number (204204).

2⁸¹³⁸⁸⁷ is an apocalyptic number.

813887 is a deficient number, since it is larger than the sum of its proper divisors (2929).

813887 is a wasteful number, since it uses less digits than its factorization.

813887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2928.

The product of its digits is 10752, while the sum is 35.

The square root of 813887 is about 902.1568599750. The cubic root of 813887 is about 93.3658460991.

The spelling of 813887 in words is "eight hundred thirteen thousand, eight hundred eighty-seven".