21204033231 has 16 divisors (see below), whose sum is σ = 29763881600. Its totient is φ = 13390295328.

The previous prime is 21204033199. The next prime is 21204033251. The reversal of 21204033231 is 13233040212.

It is not a de Polignac number, because 21204033231 - 2⁵ = 21204033199 is a prime.

It is a super-2 number, since 2×21204033231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21204033198 and 21204033207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21204033251) 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, 536025 + ... + 574221.

It is an arithmetic number, because the mean of its divisors is an integer number (1860242600).

Almost surely, 2^21204033231 is an apocalyptic number.

21204033231 is a deficient number, since it is larger than the sum of its proper divisors (8559848369).

21204033231 is a wasteful number, since it uses less digits than its factorization.

21204033231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47958.

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

Adding to 21204033231 its reverse (13233040212), we get a palindrome (34437073443).

The spelling of 21204033231 in words is "twenty-one billion, two hundred four million, thirty-three thousand, two hundred thirty-one".