20391315 has 16 divisors (see below), whose sum is σ = 37287168. Its totient is φ = 9321696.

The previous prime is 20391307. The next prime is 20391323. The reversal of 20391315 is 51319302.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20391307) and next prime (20391323).

It is not a de Polignac number, because 20391315 - 2³ = 20391307 is a prime.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 96997 + ... + 97206.

It is an arithmetic number, because the mean of its divisors is an integer number (2330448).

Almost surely, 2^20391315 is an apocalyptic number.

20391315 is a deficient number, since it is larger than the sum of its proper divisors (16895853).

20391315 is a wasteful number, since it uses less digits than its factorization.

20391315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194218.

The product of its (nonzero) digits is 810, while the sum is 24.

The square root of 20391315 is about 4515.6743682422. The cubic root of 20391315 is about 273.2006602140.

It can be divided in two parts, 20391 and 315, that added together give a triangular number (20706 = T₂₀₃).

The spelling of 20391315 in words is "twenty million, three hundred ninety-one thousand, three hundred fifteen".