21021121232 has 20 divisors (see below), whose sum is σ = 41021436960. Its totient is φ = 10434943968.

The previous prime is 21021121201. The next prime is 21021121241. The reversal of 21021121232 is 23212112012.

It is a self number, because there is not a number n which added to its sum of digits gives 21021121232.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4723748 + ... + 4728195.

It is an arithmetic number, because the mean of its divisors is an integer number (2051071848).

Almost surely, 2^21021121232 is an apocalyptic number.

It is an amenable number.

21021121232 is a deficient number, since it is larger than the sum of its proper divisors (20000315728).

21021121232 is a wasteful number, since it uses less digits than its factorization.

21021121232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9452090 (or 9452084 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21021121232 its reverse (23212112012), we get a palindrome (44233233244).

The spelling of 21021121232 in words is "twenty-one billion, twenty-one million, one hundred twenty-one thousand, two hundred thirty-two".