20085731 has 4 divisors (see below), whose sum is σ = 20360952. Its totient is φ = 19810512.

The previous prime is 20085727. The next prime is 20085733. The reversal of 20085731 is 13758002.

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 20085731 - 2² = 20085727 is a prime.

It is a super-2 number, since 2×20085731² = 806873179608722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20085731.

It is not an unprimeable number, because it can be changed into a prime (20085733) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 137501 + ... + 137646.

It is an arithmetic number, because the mean of its divisors is an integer number (5090238).

Almost surely, 2^20085731 is an apocalyptic number.

20085731 is a deficient number, since it is larger than the sum of its proper divisors (275221).

20085731 is an equidigital number, since it uses as much as digits as its factorization.

20085731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275220.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 20085731 is about 4481.7107224809. The cubic root of 20085731 is about 271.8290583578.

The spelling of 20085731 in words is "twenty million, eighty-five thousand, seven hundred thirty-one".