20717973 has 6 divisors (see below), whose sum is σ = 29925974. Its totient is φ = 13811976.

The previous prime is 20717969. The next prime is 20717989. The reversal of 20717973 is 37971702.

It can be written as a sum of positive squares in only one way, i.e., 20629764 + 88209 = 4542^2 + 297^2 .

It is not a de Polignac number, because 20717973 - 2² = 20717969 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20717903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1150990 + ... + 1151007.

Almost surely, 2^20717973 is an apocalyptic number.

It is an amenable number.

20717973 is a deficient number, since it is larger than the sum of its proper divisors (9208001).

20717973 is a wasteful number, since it uses less digits than its factorization.

20717973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2302003 (or 2302000 counting only the distinct ones).

The product of its (nonzero) digits is 18522, while the sum is 36.

The square root of 20717973 is about 4551.7000120834. The cubic root of 20717973 is about 274.6517818452.

The spelling of 20717973 in words is "twenty million, seven hundred seventeen thousand, nine hundred seventy-three".