20866625 has 16 divisors (see below), whose sum is σ = 28046928. Its totient is φ = 15408000.

The previous prime is 20866621. The next prime is 20866639. The reversal of 20866625 is 52666802.

It is a Cunningham number, because it is equal to 4568²+1.

It can be written as a sum of positive squares in 8 ways, for example, as 11082241 + 9784384 = 3329^2 + 3128^2 .

It is not a de Polignac number, because 20866625 - 2² = 20866621 is a prime.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20866621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4796 + ... + 8045.

It is an arithmetic number, because the mean of its divisors is an integer number (1752933).

Almost surely, 2^20866625 is an apocalyptic number.

20866625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20866625 is a deficient number, since it is larger than the sum of its proper divisors (7180303).

20866625 is a wasteful number, since it uses less digits than its factorization.

20866625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12869 (or 12859 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 35.

The square root of 20866625 is about 4568.0001094571. Note that the first 3 decimals coincide. The cubic root of 20866625 is about 275.3070949532.

The spelling of 20866625 in words is "twenty million, eight hundred sixty-six thousand, six hundred twenty-five".