213123013021 has 16 divisors (see below), whose sum is σ = 219761060400. Its totient is φ = 206532039168.

The previous prime is 213123013013. The next prime is 213123013039. The reversal of 213123013021 is 120310321312.

It can be written as a sum of positive squares in 8 ways, for example, as 126728168121 + 86394844900 = 355989^2 + 293930^2 .

It is a cyclic number.

It is not a de Polignac number, because 213123013021 - 2³ = 213123013013 is a prime.

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 213123013021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213123013001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21991545 + ... + 22001233.

It is an arithmetic number, because the mean of its divisors is an integer number (13735066275).

Almost surely, 2^213123013021 is an apocalyptic number.

It is an amenable number.

213123013021 is a deficient number, since it is larger than the sum of its proper divisors (6638047379).

213123013021 is a wasteful number, since it uses less digits than its factorization.

213123013021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12048.

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

Adding to 213123013021 its reverse (120310321312), we get a palindrome (333433334333).

The spelling of 213123013021 in words is "two hundred thirteen billion, one hundred twenty-three million, thirteen thousand, twenty-one".