21002433231 has 16 divisors (see below), whose sum is σ = 30161206656. Its totient is φ = 12922917216.

The previous prime is 21002433223. The next prime is 21002433253. The reversal of 21002433231 is 13233420012.

It is not a de Polignac number, because 21002433231 - 2³ = 21002433223 is a prime.

It is a super-2 number, since 2×21002433231² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21002433198 and 21002433207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002433271) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 319516 + ... + 379598.

It is an arithmetic number, because the mean of its divisors is an integer number (1885075416).

Almost surely, 2^21002433231 is an apocalyptic number.

21002433231 is a deficient number, since it is larger than the sum of its proper divisors (9158773425).

21002433231 is a wasteful number, since it uses less digits than its factorization.

21002433231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69062.

The product of its (nonzero) digits is 864, while the sum is 21.

Adding to 21002433231 its reverse (13233420012), we get a palindrome (34235853243).

The spelling of 21002433231 in words is "twenty-one billion, two million, four hundred thirty-three thousand, two hundred thirty-one".