20685924 has 144 divisors (see below), whose sum is σ = 64576512. Its totient is φ = 5455296.

The previous prime is 20685919. The next prime is 20685971. The reversal of 20685924 is 42958602.

It is a happy number.

20685924 is a `hidden beast` number, since 2 + 0 + 68 + 592 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 249187 + ... + 249269.

It is an arithmetic number, because the mean of its divisors is an integer number (448448).

Almost surely, 2^20685924 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20685924, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32288256).

20685924 is an abundant number, since it is smaller than the sum of its proper divisors (43890588).

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

20685924 is a wasteful number, since it uses less digits than its factorization.

20685924 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 20685924 is about 4548.1780967768. The cubic root of 20685924 is about 274.5100875188.

It can be divided in two parts, 20685 and 924, that added together give a square (21609 = 147²).

The spelling of 20685924 in words is "twenty million, six hundred eighty-five thousand, nine hundred twenty-four".