21241233431 has 16 divisors (see below), whose sum is σ = 23366878080. Its totient is φ = 19148361120.

The previous prime is 21241233427. The next prime is 21241233451. The reversal of 21241233431 is 13433214212.

It is a cyclic number.

It is not a de Polignac number, because 21241233431 - 2² = 21241233427 is a prime.

It is a super-2 number, since 2×21241233431² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21241233431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21241233451) 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, 1342241 + ... + 1357973.

It is an arithmetic number, because the mean of its divisors is an integer number (1460429880).

Almost surely, 2^21241233431 is an apocalyptic number.

21241233431 is a deficient number, since it is larger than the sum of its proper divisors (2125644649).

21241233431 is a wasteful number, since it uses less digits than its factorization.

21241233431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16766.

The product of its digits is 3456, while the sum is 26.

Adding to 21241233431 its reverse (13433214212), we get a palindrome (34674447643).

The spelling of 21241233431 in words is "twenty-one billion, two hundred forty-one million, two hundred thirty-three thousand, four hundred thirty-one".