20872389 has 4 divisors (see below), whose sum is σ = 27829856. Its totient is φ = 13914924.

The previous prime is 20872387. The next prime is 20872409. The reversal of 20872389 is 98327802.

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 not a de Polignac number, because 20872389 - 2¹ = 20872387 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 (20872381) 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, 3478729 + ... + 3478734.

It is an arithmetic number, because the mean of its divisors is an integer number (6957464).

Almost surely, 2^20872389 is an apocalyptic number.

It is an amenable number.

20872389 is a deficient number, since it is larger than the sum of its proper divisors (6957467).

20872389 is an equidigital number, since it uses as much as digits as its factorization.

20872389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6957466.

The product of its (nonzero) digits is 48384, while the sum is 39.

The square root of 20872389 is about 4568.6309765618. The cubic root of 20872389 is about 275.3324420326.

The spelling of 20872389 in words is "twenty million, eight hundred seventy-two thousand, three hundred eighty-nine".