21132321320 has 32 divisors (see below), whose sum is σ = 51870244320. Its totient is φ = 7684480320.

The previous prime is 21132321307. The next prime is 21132321383. The reversal of 21132321320 is 2312323112.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21132321292 and 21132321301.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24013562 + ... + 24014441.

It is an arithmetic number, because the mean of its divisors is an integer number (1620945135).

Almost surely, 2^21132321320 is an apocalyptic number.

21132321320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21132321320 is an abundant number, since it is smaller than the sum of its proper divisors (30737923000).

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

21132321320 is a wasteful number, since it uses less digits than its factorization.

21132321320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48028025 (or 48028021 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 21132321320 its reverse (2312323112), we get a palindrome (23444644432).

The spelling of 21132321320 in words is "twenty-one billion, one hundred thirty-two million, three hundred twenty-one thousand, three hundred twenty".