21013132320 has 96 divisors (see below), whose sum is σ = 73545978240. Its totient is φ = 5603500800.

The previous prime is 21013132313. The next prime is 21013132321. The reversal of 21013132320 is 2323131012.

21013132320 is a `hidden beast` number, since 210 + 1 + 3 + 132 + 320 = 666.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21013132293 and 21013132302.

It is not an unprimeable number, because it can be changed into a prime (21013132321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2427756 + ... + 2436395.

It is an arithmetic number, because the mean of its divisors is an integer number (766103940).

Almost surely, 2^21013132320 is an apocalyptic number.

21013132320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21013132320 is an abundant number, since it is smaller than the sum of its proper divisors (52532845920).

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

21013132320 is a wasteful number, since it uses less digits than its factorization.

21013132320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4864175 (or 4864161 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21013132320 its reverse (2323131012), we get a palindrome (23336263332).

The spelling of 21013132320 in words is "twenty-one billion, thirteen million, one hundred thirty-two thousand, three hundred twenty".