21003121232 has 20 divisors (see below), whose sum is σ = 42462832800. Its totient is φ = 10044970848.

The previous prime is 21003121213. The next prime is 21003121241. The reversal of 21003121232 is 23212130012.

It is a super-2 number, since 2×21003121232² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21003121232.

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, 28536482 + ... + 28537217.

It is an arithmetic number, because the mean of its divisors is an integer number (2123141640).

Almost surely, 2^21003121232 is an apocalyptic number.

It is an amenable number.

21003121232 is an abundant number, since it is smaller than the sum of its proper divisors (21459711568).

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

21003121232 is a wasteful number, since it uses less digits than its factorization.

21003121232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57073730 (or 57073724 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21003121232 its reverse (23212130012), we get a palindrome (44215251244).

The spelling of 21003121232 in words is "twenty-one billion, three million, one hundred twenty-one thousand, two hundred thirty-two".