20925390 has 16 divisors (see below), whose sum is σ = 50221008. Its totient is φ = 5580096.

The previous prime is 20925389. The next prime is 20925433. The reversal of 20925390 is 9352902.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 697513 = 20925390 / (2 + 0 + 9 + 2 + 5 + 3 + 9 + 0).

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, 348727 + ... + 348786.

It is an arithmetic number, because the mean of its divisors is an integer number (3138813).

Almost surely, 2^20925390 is an apocalyptic number.

20925390 is an abundant number, since it is smaller than the sum of its proper divisors (29295618).

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

20925390 is a wasteful number, since it uses less digits than its factorization.

20925390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 697523.

The product of its (nonzero) digits is 4860, while the sum is 30.

The square root of 20925390 is about 4574.4278330738. The cubic root of 20925390 is about 275.5652944755.

The spelling of 20925390 in words is "twenty million, nine hundred twenty-five thousand, three hundred ninety".