21372043967 has 4 divisors (see below), whose sum is σ = 21375245760. Its totient is φ = 21368842176.

The previous prime is 21372043921. The next prime is 21372043991. The reversal of 21372043967 is 76934027312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21372043967 - 2³⁴ = 4192174783 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 (21372043367) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1590863 + ... + 1604240.

It is an arithmetic number, because the mean of its divisors is an integer number (5343811440).

Almost surely, 2^21372043967 is an apocalyptic number.

21372043967 is a deficient number, since it is larger than the sum of its proper divisors (3201793).

21372043967 is an equidigital number, since it uses as much as digits as its factorization.

21372043967 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3201792.

The product of its (nonzero) digits is 381024, while the sum is 44.

The spelling of 21372043967 in words is "twenty-one billion, three hundred seventy-two million, forty-three thousand, nine hundred sixty-seven".