21123431241 has 64 divisors (see below), whose sum is σ = 33190671360. Its totient is φ = 11811744000.

The previous prime is 21123431237. The next prime is 21123431291. The reversal of 21123431241 is 14213432112.

It is not a de Polignac number, because 21123431241 - 2² = 21123431237 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21123431291) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11349651 + ... + 11351511.

It is an arithmetic number, because the mean of its divisors is an integer number (518604240).

Almost surely, 2^21123431241 is an apocalyptic number.

It is an amenable number.

21123431241 is a deficient number, since it is larger than the sum of its proper divisors (12067240119).

21123431241 is a wasteful number, since it uses less digits than its factorization.

21123431241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2358.

The product of its digits is 1152, while the sum is 24.

Adding to 21123431241 its reverse (14213432112), we get a palindrome (35336863353).

The spelling of 21123431241 in words is "twenty-one billion, one hundred twenty-three million, four hundred thirty-one thousand, two hundred forty-one".