20685972 has 24 divisors (see below), whose sum is σ = 48452992. Its totient is φ = 6868800.

The previous prime is 20685971. The next prime is 20685983. The reversal of 20685972 is 27958602.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 20685972.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20685971) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72 + ... + 6432.

Almost surely, 2^20685972 is an apocalyptic number.

It is an amenable number.

20685972 is an abundant number, since it is smaller than the sum of its proper divisors (27767020).

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

20685972 is a wasteful number, since it uses less digits than its factorization.

20685972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6639 (or 6637 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 39.

The square root of 20685972 is about 4548.1833736119. The cubic root of 20685972 is about 274.5102998448.

The spelling of 20685972 in words is "twenty million, six hundred eighty-five thousand, nine hundred seventy-two".