21031121232 has 240 divisors, whose sum is σ = 66778350912. Its totient is φ = 6354754560.

The previous prime is 21031121201. The next prime is 21031121269. The reversal of 21031121232 is 23212113012.

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 47 ways as a sum of consecutive naturals, for example, 26387458 + ... + 26388254.

Almost surely, 2^21031121232 is an apocalyptic number.

21031121232 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21031121232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33389175456).

21031121232 is an abundant number, since it is smaller than the sum of its proper divisors (45747229680).

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

21031121232 is a wasteful number, since it uses less digits than its factorization.

21031121232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1448 (or 1430 counting only the distinct ones).

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

Adding to 21031121232 its reverse (23212113012), we get a palindrome (44243234244).

The spelling of 21031121232 in words is "twenty-one billion, thirty-one million, one hundred twenty-one thousand, two hundred thirty-two".