21232121232 has 80 divisors (see below), whose sum is σ = 62834625152. Its totient is φ = 6051870720.

The previous prime is 21232121213. The next prime is 21232121249. The reversal of 21232121232 is 23212123212.

21232121232 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a nude number because it is divisible by every one of its digits.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 21232121199 and 21232121208.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66408 + ... + 216504.

Almost surely, 2^21232121232 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21232121232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31417312576).

21232121232 is an abundant number, since it is smaller than the sum of its proper divisors (41602503920).

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

21232121232 is a wasteful number, since it uses less digits than its factorization.

21232121232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150536 (or 150530 counting only the distinct ones).

The product of its digits is 576, while the sum is 21.

Adding to 21232121232 its reverse (23212123212), we get a palindrome (44444244444).

The spelling of 21232121232 in words is "twenty-one billion, two hundred thirty-two million, one hundred twenty-one thousand, two hundred thirty-two".