21987951304 has 64 divisors (see below), whose sum is σ = 45508962240. Its totient is φ = 9876418560.

The previous prime is 21987951287. The next prime is 21987951313. The reversal of 21987951304 is 40315978912.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4074432 + ... + 4079824.

It is an arithmetic number, because the mean of its divisors is an integer number (711077535).

Almost surely, 2^21987951304 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21987951304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22754481120).

21987951304 is an abundant number, since it is smaller than the sum of its proper divisors (23521010936).

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

21987951304 is a wasteful number, since it uses less digits than its factorization.

21987951304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5950 (or 5946 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 49.

The spelling of 21987951304 in words is "twenty-one billion, nine hundred eighty-seven million, nine hundred fifty-one thousand, three hundred four".