321381046781 has 2 divisors, whose sum is σ = 321381046782. Its totient is φ = 321381046780.

The previous prime is 321381046739. The next prime is 321381046783. The reversal of 321381046781 is 187640183123.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 167963907556 + 153417139225 = 409834^2 + 391685^2 .

It is a cyclic number.

It is not a de Polignac number, because 321381046781 - 2¹⁰ = 321381045757 is a prime.

It is a super-2 number, since 2×321381046781² (a number of 24 digits) contains 22 as substring.

Together with 321381046783, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321381046783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160690523390 + 160690523391.

It is an arithmetic number, because the mean of its divisors is an integer number (160690523391).

Almost surely, 2^321381046781 is an apocalyptic number.

It is an amenable number.

321381046781 is a deficient number, since it is larger than the sum of its proper divisors (1).

321381046781 is an equidigital number, since it uses as much as digits as its factorization.

321381046781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 193536, while the sum is 44.

The spelling of 321381046781 in words is "three hundred twenty-one billion, three hundred eighty-one million, forty-six thousand, seven hundred eighty-one".