321320402531 has 2 divisors, whose sum is σ = 321320402532. Its totient is φ = 321320402530.

The previous prime is 321320402479. The next prime is 321320402539. The reversal of 321320402531 is 135204023123.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 321320402531 - 2¹⁸ = 321320140387 is a prime.

It is a super-2 number, since 2×321320402531² (a number of 24 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 321320402531.

It is not a weakly prime, because it can be changed into another prime (321320402539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160660201265 + 160660201266.

It is an arithmetic number, because the mean of its divisors is an integer number (160660201266).

Almost surely, 2^321320402531 is an apocalyptic number.

321320402531 is a deficient number, since it is larger than the sum of its proper divisors (1).

321320402531 is an equidigital number, since it uses as much as digits as its factorization.

321320402531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 26.

Adding to 321320402531 its reverse (135204023123), we get a palindrome (456524425654).

The spelling of 321320402531 in words is "three hundred twenty-one billion, three hundred twenty million, four hundred two thousand, five hundred thirty-one".