21958934839 has 4 divisors (see below), whose sum is σ = 22098800824. Its totient is φ = 21819068856.

The previous prime is 21958934827. The next prime is 21958934863. The reversal of 21958934839 is 93843985912.

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 21958934839 - 2¹⁷ = 21958803767 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 (21958934819) 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, 69932757 + ... + 69933070.

It is an arithmetic number, because the mean of its divisors is an integer number (5524700206).

Almost surely, 2^21958934839 is an apocalyptic number.

21958934839 is a deficient number, since it is larger than the sum of its proper divisors (139865985).

21958934839 is a wasteful number, since it uses less digits than its factorization.

21958934839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139865984.

The product of its digits is 16796160, while the sum is 61.

The spelling of 21958934839 in words is "twenty-one billion, nine hundred fifty-eight million, nine hundred thirty-four thousand, eight hundred thirty-nine".