21503534000 has 160 divisors (see below), whose sum is σ = 57189839616. Its totient is φ = 7770393600.

The previous prime is 21503533991. The next prime is 21503534029. The reversal of 21503534000 is 43530512.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1213202 + ... + 1230798.

Almost surely, 2^21503534000 is an apocalyptic number.

21503534000 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 21503534000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28594919808).

21503534000 is an abundant number, since it is smaller than the sum of its proper divisors (35686305616).

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

21503534000 is a wasteful number, since it uses less digits than its factorization.

21503534000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17680 (or 17664 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 23.

The spelling of 21503534000 in words is "twenty-one billion, five hundred three million, five hundred thirty-four thousand".