20917925 has 24 divisors (see below), whose sum is σ = 30938496. Its totient is φ = 13717440.

The previous prime is 20917891. The next prime is 20917933. The reversal of 20917925 is 52971902.

It is not a de Polignac number, because 20917925 - 2⁶ = 20917861 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1427 + ... + 6623.

It is an arithmetic number, because the mean of its divisors is an integer number (1289104).

Almost surely, 2^20917925 is an apocalyptic number.

20917925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20917925 is a deficient number, since it is larger than the sum of its proper divisors (10020571).

20917925 is a wasteful number, since it uses less digits than its factorization.

20917925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5237 (or 5232 counting only the distinct ones).

The product of its (nonzero) digits is 11340, while the sum is 35.

The square root of 20917925 is about 4573.6118112494. The cubic root of 20917925 is about 275.5325218551.

The spelling of 20917925 in words is "twenty million, nine hundred seventeen thousand, nine hundred twenty-five".