21503432331 has 12 divisors (see below), whose sum is σ = 31074641208. Its totient is φ = 14329101024.

The previous prime is 21503432287. The next prime is 21503432333. The reversal of 21503432331 is 13323430512.

It is not a de Polignac number, because 21503432331 - 2¹¹ = 21503430283 is a prime.

It is a super-2 number, since 2×21503432331² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21503432295 and 21503432304.

It is not an unprimeable number, because it can be changed into a prime (21503432333) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 522450 + ... + 562103.

It is an arithmetic number, because the mean of its divisors is an integer number (2589553434).

Almost surely, 2^21503432331 is an apocalyptic number.

21503432331 is a deficient number, since it is larger than the sum of its proper divisors (9571208877).

21503432331 is a wasteful number, since it uses less digits than its factorization.

21503432331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1086762 (or 1086759 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 27.

Adding to 21503432331 its reverse (13323430512), we get a palindrome (34826862843).

The spelling of 21503432331 in words is "twenty-one billion, five hundred three million, four hundred thirty-two thousand, three hundred thirty-one".