20686172 has 12 divisors (see below), whose sum is σ = 38985576. Its totient is φ = 9547440.

The previous prime is 20686147. The next prime is 20686189. The reversal of 20686172 is 27168602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 198854 + ... + 198957.

It is an arithmetic number, because the mean of its divisors is an integer number (3248798).

Almost surely, 2^20686172 is an apocalyptic number.

It is an amenable number.

20686172 is a deficient number, since it is larger than the sum of its proper divisors (18299404).

20686172 is a wasteful number, since it uses less digits than its factorization.

20686172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397828 (or 397826 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 20686172 is about 4548.2053603592. The cubic root of 20686172 is about 274.5111845326.

The spelling of 20686172 in words is "twenty million, six hundred eighty-six thousand, one hundred seventy-two".