21321503632 has 160 divisors (see below), whose sum is σ = 51553200384. Its totient is φ = 8392704000.

The previous prime is 21321503617. The next prime is 21321503647. The reversal of 21321503632 is 23630512312.

It is an interprime number because it is at equal distance from previous prime (21321503617) and next prime (21321503647).

It is a self number, because there is not a number n which added to its sum of digits gives 21321503632.

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, 15596613 + ... + 15597979.

Almost surely, 2^21321503632 is an apocalyptic number.

21321503632 is a gapful number since it is divisible by the number (22) 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 21321503632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25776600192).

21321503632 is an abundant number, since it is smaller than the sum of its proper divisors (30231696752).

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

21321503632 is a wasteful number, since it uses less digits than its factorization.

21321503632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1817 (or 1811 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 28.

The spelling of 21321503632 in words is "twenty-one billion, three hundred twenty-one million, five hundred three thousand, six hundred thirty-two".