21231232110 has 128 divisors (see below), whose sum is σ = 62341747200. Its totient is φ = 5098786560.

The previous prime is 21231232049. The next prime is 21231232133. The reversal of 21231232110 is 1123213212.

21231232110 is a `hidden beast` number, since 21 + 2 + 312 + 321 + 10 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 284386 + ... + 351194.

It is an arithmetic number, because the mean of its divisors is an integer number (487044900).

Almost surely, 2^21231232110 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21231232110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31170873600).

21231232110 is an abundant number, since it is smaller than the sum of its proper divisors (41110515090).

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

21231232110 is a wasteful number, since it uses less digits than its factorization.

21231232110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66943 (or 66937 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21231232110 its reverse (1123213212), we get a palindrome (22354445322).

The spelling of 21231232110 in words is "twenty-one billion, two hundred thirty-one million, two hundred thirty-two thousand, one hundred ten".