21323887500 has 144 divisors (see below), whose sum is σ = 63370006560. Its totient is φ = 5578560000.

The previous prime is 21323887493. The next prime is 21323887513. The reversal of 21323887500 is 578832312.

It is a super-2 number, since 2×21323887500² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1982136 + ... + 1992864.

It is an arithmetic number, because the mean of its divisors is an integer number (440069490).

Almost surely, 2^21323887500 is an apocalyptic number.

21323887500 is a gapful number since it is divisible by the number (20) 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 21323887500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31685003280).

21323887500 is an abundant number, since it is smaller than the sum of its proper divisors (42046119060).

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

21323887500 is a wasteful number, since it uses less digits than its factorization.

21323887500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10814 (or 10792 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 39.

The spelling of 21323887500 in words is "twenty-one billion, three hundred twenty-three million, eight hundred eighty-seven thousand, five hundred".