21739130437 has 4 divisors (see below), whose sum is σ = 21832431660. Its totient is φ = 21645829216.

The previous prime is 21739130429. The next prime is 21739130447. The reversal of 21739130437 is 73403193712.

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

It can be written as a sum of positive squares in 2 ways, for example, as 15453970596 + 6285159841 = 124314^2 + 79279^2 .

It is a cyclic number.

It is not a de Polignac number, because 21739130437 - 2³ = 21739130429 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21739130437.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21739130417) 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, 46650262 + ... + 46650727.

It is an arithmetic number, because the mean of its divisors is an integer number (5458107915).

Almost surely, 2^21739130437 is an apocalyptic number.

It is an amenable number.

21739130437 is a deficient number, since it is larger than the sum of its proper divisors (93301223).

21739130437 is an equidigital number, since it uses as much as digits as its factorization.

21739130437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93301222.

The product of its (nonzero) digits is 95256, while the sum is 40.

The spelling of 21739130437 in words is "twenty-one billion, seven hundred thirty-nine million, one hundred thirty thousand, four hundred thirty-seven".