20872373021 has 4 divisors (see below), whose sum is σ = 21316466112. Its totient is φ = 20428279932.

The previous prime is 20872373009. The next prime is 20872373051. The reversal of 20872373021 is 12037327802.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20872373021 - 2⁶ = 20872372957 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 (20872373051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 222046475 + ... + 222046568.

It is an arithmetic number, because the mean of its divisors is an integer number (5329116528).

Almost surely, 2^20872373021 is an apocalyptic number.

It is an amenable number.

20872373021 is a deficient number, since it is larger than the sum of its proper divisors (444093091).

20872373021 is an equidigital number, since it uses as much as digits as its factorization.

20872373021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 444093090.

The product of its (nonzero) digits is 28224, while the sum is 35.

The spelling of 20872373021 in words is "twenty billion, eight hundred seventy-two million, three hundred seventy-three thousand, twenty-one".