21123032013 has 40 divisors (see below), whose sum is σ = 33260615520. Its totient is φ = 13322504160.

The previous prime is 21123031973. The next prime is 21123032017. The reversal of 21123032013 is 31023032112.

It is not a de Polignac number, because 21123032013 - 2¹⁴ = 21123015629 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21123032017) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1155958 + ... + 1174088.

It is an arithmetic number, because the mean of its divisors is an integer number (831515388).

Almost surely, 2^21123032013 is an apocalyptic number.

It is an amenable number.

21123032013 is a deficient number, since it is larger than the sum of its proper divisors (12137583507).

21123032013 is a wasteful number, since it uses less digits than its factorization.

21123032013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18919 (or 18910 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21123032013 its reverse (31023032112), we get a palindrome (52146064125).

Subtracting 21123032013 from its reverse (31023032112), we obtain a palindrome (9900000099).

The spelling of 21123032013 in words is "twenty-one billion, one hundred twenty-three million, thirty-two thousand, thirteen".