20681972 has 12 divisors (see below), whose sum is σ = 36552516. Its totient is φ = 10238400.

The previous prime is 20681957. The next prime is 20681993. The reversal of 20681972 is 27918602.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 9897316 + 10784656 = 3146^2 + 3284^2 .

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, 25193 + ... + 26000.

It is an arithmetic number, because the mean of its divisors is an integer number (3046043).

Almost surely, 2^20681972 is an apocalyptic number.

It is an amenable number.

20681972 is a deficient number, since it is larger than the sum of its proper divisors (15870544).

20681972 is a wasteful number, since it uses less digits than its factorization.

20681972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51298 (or 51296 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 20681972 is about 4547.7436163443. The cubic root of 20681972 is about 274.4926048906.

The spelling of 20681972 in words is "twenty million, six hundred eighty-one thousand, nine hundred seventy-two".