21130123213 has 4 divisors (see below), whose sum is σ = 21132292000. Its totient is φ = 21127954428.

The previous prime is 21130123211. The next prime is 21130123283. The reversal of 21130123213 is 31232103112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21130123213 - 2¹ = 21130123211 is a prime.

It is a super-2 number, since 2×21130123213² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21130123211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1069713 + ... + 1089286.

It is an arithmetic number, because the mean of its divisors is an integer number (5283073000).

Almost surely, 2^21130123213 is an apocalyptic number.

It is an amenable number.

21130123213 is a deficient number, since it is larger than the sum of its proper divisors (2168787).

21130123213 is an equidigital number, since it uses as much as digits as its factorization.

21130123213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2168786.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21130123213 its reverse (31232103112), we get a palindrome (52362226325).

The spelling of 21130123213 in words is "twenty-one billion, one hundred thirty million, one hundred twenty-three thousand, two hundred thirteen".