20981672 has 16 divisors (see below), whose sum is σ = 41655060. Its totient is φ = 9873664.

The previous prime is 20981671. The next prime is 20981677. The reversal of 20981672 is 27618902.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20124196 + 857476 = 4486^2 + 926^2 .

It is not an unprimeable number, because it can be changed into a prime (20981671) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77003 + ... + 77274.

Almost surely, 2^20981672 is an apocalyptic number.

It is an amenable number.

20981672 is a deficient number, since it is larger than the sum of its proper divisors (20673388).

20981672 is a wasteful number, since it uses less digits than its factorization.

20981672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154300 (or 154296 counting only the distinct ones).

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

The square root of 20981672 is about 4580.5755096931. The cubic root of 20981672 is about 275.8121314794.

The spelling of 20981672 in words is "twenty million, nine hundred eighty-one thousand, six hundred seventy-two".