21534700000 has 144 divisors (see below), whose sum is σ = 57812581008. Its totient is φ = 7830400000.

The previous prime is 21534699947. The next prime is 21534700021. The reversal of 21534700000 is 743512.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent 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, 1090212 + ... + 1109788.

It is an arithmetic number, because the mean of its divisors is an integer number (401476257).

Almost surely, 2^21534700000 is an apocalyptic number.

21534700000 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 21534700000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28906290504).

21534700000 is an abundant number, since it is smaller than the sum of its proper divisors (36277881008).

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

21534700000 is an equidigital number, since it uses as much as digits as its factorization.

21534700000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19623 (or 19595 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 22.

The spelling of 21534700000 in words is "twenty-one billion, five hundred thirty-four million, seven hundred thousand".