20689925 has 12 divisors (see below), whose sum is σ = 25791876. Its totient is φ = 16464000.

The previous prime is 20689913. The next prime is 20689967. The reversal of 20689925 is 52998602.

It can be written as a sum of positive squares in 6 ways, for example, as 178084 + 20511841 = 422^2 + 4529^2 .

It is not a de Polignac number, because 20689925 - 2⁴ = 20689909 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2825 + ... + 7025.

It is an arithmetic number, because the mean of its divisors is an integer number (2149323).

Almost surely, 2^20689925 is an apocalyptic number.

20689925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20689925 is a deficient number, since it is larger than the sum of its proper divisors (5101951).

20689925 is a wasteful number, since it uses less digits than its factorization.

20689925 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4408 (or 4403 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 41.

The square root of 20689925 is about 4548.6179219627. The cubic root of 20689925 is about 274.5277846424.

The spelling of 20689925 in words is "twenty million, six hundred eighty-nine thousand, nine hundred twenty-five".