21310221213 has 12 divisors (see below), whose sum is σ = 31532197788. Its totient is φ = 13860306240.

The previous prime is 21310221197. The next prime is 21310221239. The reversal of 21310221213 is 31212201312.

It can be written as a sum of positive squares in 2 ways, for example, as 10556946009 + 10753275204 = 102747^2 + 103698^2 .

It is not a de Polignac number, because 21310221213 - 2⁴ = 21310221197 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21310221113) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28875270 + ... + 28876007.

It is an arithmetic number, because the mean of its divisors is an integer number (2627683149).

Almost surely, 2^21310221213 is an apocalyptic number.

It is an amenable number.

21310221213 is a deficient number, since it is larger than the sum of its proper divisors (10221976575).

21310221213 is a wasteful number, since it uses less digits than its factorization.

21310221213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57751324 (or 57751321 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21310221213 its reverse (31212201312), we get a palindrome (52522422525).

The spelling of 21310221213 in words is "twenty-one billion, three hundred ten million, two hundred twenty-one thousand, two hundred thirteen".