21938479937 has 16 divisors (see below), whose sum is σ = 24493665600. Its totient is φ = 19481067840.

The previous prime is 21938479921. The next prime is 21938479951. The reversal of 21938479937 is 73997483912.

It is a cyclic number.

It is not a de Polignac number, because 21938479937 - 2⁴ = 21938479921 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 21938479937.

It is not an unprimeable number, because it can be changed into a prime (21938479037) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5762 + ... + 209547.

It is an arithmetic number, because the mean of its divisors is an integer number (1530854100).

Almost surely, 2^21938479937 is an apocalyptic number.

It is an amenable number.

21938479937 is a deficient number, since it is larger than the sum of its proper divisors (2555185663).

21938479937 is a wasteful number, since it uses less digits than its factorization.

21938479937 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215536.

The product of its digits is 20575296, while the sum is 62.

The spelling of 21938479937 in words is "twenty-one billion, nine hundred thirty-eight million, four hundred seventy-nine thousand, nine hundred thirty-seven".