21319597938 has 48 divisors (see below), whose sum is σ = 45177760800. Its totient is φ = 6706132992.

The previous prime is 21319597931. The next prime is 21319597939. The reversal of 21319597938 is 83979591312.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21319597931) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 537513 + ... + 575811.

It is an arithmetic number, because the mean of its divisors is an integer number (941203350).

Almost surely, 2^21319597938 is an apocalyptic number.

21319597938 is an abundant number, since it is smaller than the sum of its proper divisors (23858162862).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21319597938 is a wasteful number, since it uses less digits than its factorization.

21319597938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38599 (or 38580 counting only the distinct ones).

The product of its digits is 3674160, while the sum is 57.

It can be divided in two parts, 2131 and 9597938, that added together give a palindrome (9600069).

The spelling of 21319597938 in words is "twenty-one billion, three hundred nineteen million, five hundred ninety-seven thousand, nine hundred thirty-eight".