21231023013 has 6 divisors (see below), whose sum is σ = 30667033254. Its totient is φ = 14154015336.

The previous prime is 21231022991. The next prime is 21231023017. The reversal of 21231023013 is 31032013212.

It can be written as a sum of positive squares in only one way, i.e., 17369394849 + 3861628164 = 131793^2 + 62142^2 .

It is not a de Polignac number, because 21231023013 - 2¹³ = 21231014821 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21231023017) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1179501270 + ... + 1179501287.

It is an arithmetic number, because the mean of its divisors is an integer number (5111172209).

Almost surely, 2^21231023013 is an apocalyptic number.

It is an amenable number.

21231023013 is a deficient number, since it is larger than the sum of its proper divisors (9436010241).

21231023013 is a wasteful number, since it uses less digits than its factorization.

21231023013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2359002563 (or 2359002560 counting only the distinct ones).

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

Adding to 21231023013 its reverse (31032013212), we get a palindrome (52263036225).

The spelling of 21231023013 in words is "twenty-one billion, two hundred thirty-one million, twenty-three thousand, thirteen".