321213521521 has 4 divisors (see below), whose sum is σ = 321226350592. Its totient is φ = 321200692452.

The previous prime is 321213521507. The next prime is 321213521539. The reversal of 321213521521 is 125125312123.

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 321213521521 - 2¹³ = 321213513329 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 321213521521.

It is not an unprimeable number, because it can be changed into a prime (321213521581) 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, 6376905 + ... + 6427078.

It is an arithmetic number, because the mean of its divisors is an integer number (80306587648).

Almost surely, 2^321213521521 is an apocalyptic number.

It is an amenable number.

321213521521 is a deficient number, since it is larger than the sum of its proper divisors (12829071).

321213521521 is a wasteful number, since it uses less digits than its factorization.

321213521521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12829070.

The product of its digits is 3600, while the sum is 28.

Adding to 321213521521 its reverse (125125312123), we get a palindrome (446338833644).

The spelling of 321213521521 in words is "three hundred twenty-one billion, two hundred thirteen million, five hundred twenty-one thousand, five hundred twenty-one".