20872472521 has 4 divisors (see below), whose sum is σ = 20874068992. Its totient is φ = 20870876052.

The previous prime is 20872472497. The next prime is 20872472531. The reversal of 20872472521 is 12527427802.

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 20872472521 - 2¹⁷ = 20872341449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20872472531) 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, 778461 + ... + 804826.

It is an arithmetic number, because the mean of its divisors is an integer number (5218517248).

Almost surely, 2^20872472521 is an apocalyptic number.

It is an amenable number.

20872472521 is a deficient number, since it is larger than the sum of its proper divisors (1596471).

20872472521 is a wasteful number, since it uses less digits than its factorization.

20872472521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1596470.

The product of its (nonzero) digits is 125440, while the sum is 40.

The spelling of 20872472521 in words is "twenty billion, eight hundred seventy-two million, four hundred seventy-two thousand, five hundred twenty-one".