213112312021 has 4 divisors (see below), whose sum is σ = 243556928032. Its totient is φ = 182667696012.

The previous prime is 213112312003. The next prime is 213112312081. The reversal of 213112312021 is 120213211312.

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 213112312021 - 2¹⁷ = 213112180949 is a prime.

It is a super-2 number, since 2×213112312021² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 213112312021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213112312081) 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, 15222307995 + ... + 15222308008.

It is an arithmetic number, because the mean of its divisors is an integer number (60889232008).

Almost surely, 2^213112312021 is an apocalyptic number.

It is an amenable number.

213112312021 is a deficient number, since it is larger than the sum of its proper divisors (30444616011).

213112312021 is an equidigital number, since it uses as much as digits as its factorization.

213112312021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30444616010.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 213112312021 its reverse (120213211312), we get a palindrome (333325523333).

It can be divided in two parts, 21311 and 2312021, that added together give a palindrome (2333332).

The spelling of 213112312021 in words is "two hundred thirteen billion, one hundred twelve million, three hundred twelve thousand, twenty-one".