20391415 has 32 divisors (see below), whose sum is σ = 28662336. Its totient is φ = 13762560.

The previous prime is 20391407. The next prime is 20391421. The reversal of 20391415 is 51419302.

It is not a de Polignac number, because 20391415 - 2³ = 20391407 is a prime.

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 20391415.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 105559 + ... + 105751.

It is an arithmetic number, because the mean of its divisors is an integer number (895698).

Almost surely, 2^20391415 is an apocalyptic number.

20391415 is a deficient number, since it is larger than the sum of its proper divisors (8270921).

20391415 is a wasteful number, since it uses less digits than its factorization.

20391415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 339.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 20391415 is about 4515.6854407720. The cubic root of 20391415 is about 273.2011068098.

The spelling of 20391415 in words is "twenty million, three hundred ninety-one thousand, four hundred fifteen".