21672402389 has 4 divisors (see below), whose sum is σ = 23642620800. Its totient is φ = 19702183980.

The previous prime is 21672402359. The next prime is 21672402439. The reversal of 21672402389 is 98320427612.

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 a de Polignac number, because none of the positive numbers 2^k-21672402389 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 (21672402359) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 985109189 + ... + 985109210.

It is an arithmetic number, because the mean of its divisors is an integer number (5910655200).

Almost surely, 2^21672402389 is an apocalyptic number.

It is an amenable number.

21672402389 is a deficient number, since it is larger than the sum of its proper divisors (1970218411).

21672402389 is a wasteful number, since it uses less digits than its factorization.

21672402389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1970218410.

The product of its (nonzero) digits is 290304, while the sum is 44.

The spelling of 21672402389 in words is "twenty-one billion, six hundred seventy-two million, four hundred two thousand, three hundred eighty-nine".