21873953388 has 72 divisors (see below), whose sum is σ = 59422431600. Its totient is φ = 6244409472.

The previous prime is 21873953359. The next prime is 21873953399. The reversal of 21873953388 is 88335937812.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 707518 + ... + 737786.

It is an arithmetic number, because the mean of its divisors is an integer number (825311550).

Almost surely, 2^21873953388 is an apocalyptic number.

21873953388 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21873953388, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29711215800).

21873953388 is an abundant number, since it is smaller than the sum of its proper divisors (37548478212).

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

21873953388 is a wasteful number, since it uses less digits than its factorization.

21873953388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31519 (or 31510 counting only the distinct ones).

The product of its digits is 8709120, while the sum is 57.

The spelling of 21873953388 in words is "twenty-one billion, eight hundred seventy-three million, nine hundred fifty-three thousand, three hundred eighty-eight".