20723972 has 6 divisors (see below), whose sum is σ = 36266958. Its totient is φ = 10361984.

The previous prime is 20723939. The next prime is 20723999. The reversal of 20723972 is 27932702.

It can be written as a sum of positive squares in only one way, i.e., 10394176 + 10329796 = 3224^2 + 3214^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2590493 + ... + 2590500.

It is an arithmetic number, because the mean of its divisors is an integer number (6044493).

Almost surely, 2^20723972 is an apocalyptic number.

It is an amenable number.

20723972 is a deficient number, since it is larger than the sum of its proper divisors (15542986).

20723972 is a wasteful number, since it uses less digits than its factorization.

20723972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5180997 (or 5180995 counting only the distinct ones).

The product of its (nonzero) digits is 10584, while the sum is 32.

The square root of 20723972 is about 4552.3589489406. The cubic root of 20723972 is about 274.6782882516.

The spelling of 20723972 in words is "twenty million, seven hundred twenty-three thousand, nine hundred seventy-two".