21132213220 has 24 divisors (see below), whose sum is σ = 44400686904. Its totient is φ = 8448496896.

The previous prime is 21132213209. The next prime is 21132213247. The reversal of 21132213220 is 2231223112.

It can be written as a sum of positive squares in 4 ways, for example, as 2187994176 + 18944219044 = 46776^2 + 137638^2 .

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, 234649 + ... + 311968.

It is an arithmetic number, because the mean of its divisors is an integer number (1850028621).

Almost surely, 2^21132213220 is an apocalyptic number.

21132213220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21132213220 is an abundant number, since it is smaller than the sum of its proper divisors (23268473684).

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

21132213220 is a wasteful number, since it uses less digits than its factorization.

21132213220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 548559 (or 548557 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21132213220 its reverse (2231223112), we get a palindrome (23363436332).

The spelling of 21132213220 in words is "twenty-one billion, one hundred thirty-two million, two hundred thirteen thousand, two hundred twenty".