20731318 has 16 divisors (see below), whose sum is σ = 32944320. Its totient is φ = 9756936.

The previous prime is 20731309. The next prime is 20731327. The reversal of 20731318 is 81313702.

It is an interprime number because it is at equal distance from previous prime (20731309) and next prime (20731327).

It is a junction number, because it is equal to n+sod(n) for n = 20731292 and 20731301.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4521 + ... + 7867.

It is an arithmetic number, because the mean of its divisors is an integer number (2059020).

Almost surely, 2^20731318 is an apocalyptic number.

20731318 is a deficient number, since it is larger than the sum of its proper divisors (12213002).

20731318 is a wasteful number, since it uses less digits than its factorization.

20731318 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3531.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 20731318 is about 4553.1657118976. The cubic root of 20731318 is about 274.7107393721.

The spelling of 20731318 in words is "twenty million, seven hundred thirty-one thousand, three hundred eighteen".