809139690 has 24 divisors (see below), whose sum is σ = 2103763428. Its totient is φ = 215770560.

The previous prime is 809139619. The next prime is 809139703. The reversal of 809139690 is 96931908.

It can be written as a sum of positive squares in 2 ways, for example, as 727219089 + 81920601 = 26967^2 + 9051^2 .

It is a super-2 number, since 2×809139690² = 1309414075866592200, which contains 22 as substring.

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 a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4495131 + ... + 4495310.

Almost surely, 2^809139690 is an apocalyptic number.

809139690 is an abundant number, since it is smaller than the sum of its proper divisors (1294623738).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

809139690 is a wasteful number, since it uses less digits than its factorization.

809139690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8990454 (or 8990451 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 45.

The square root of 809139690 is about 28445.3808200910. The cubic root of 809139690 is about 931.8396122600.

The spelling of 809139690 in words is "eight hundred nine million, one hundred thirty-nine thousand, six hundred ninety".