321920040961 has 4 divisors (see below), whose sum is σ = 327994004052. Its totient is φ = 315846077872.

The previous prime is 321920040929. The next prime is 321920040971. The reversal of 321920040961 is 169040029123.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 169040029123 = 7 ⋅24148575589.

It can be written as a sum of positive squares in 2 ways, for example, as 292728609936 + 29191431025 = 541044^2 + 170855^2 .

It is a cyclic number.

It is not a de Polignac number, because 321920040961 - 2⁵ = 321920040929 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 321920040961.

It is not an unprimeable number, because it can be changed into a prime (321920040971) 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, 3036981466 + ... + 3036981571.

It is an arithmetic number, because the mean of its divisors is an integer number (81998501013).

Almost surely, 2^321920040961 is an apocalyptic number.

It is an amenable number.

321920040961 is a deficient number, since it is larger than the sum of its proper divisors (6073963091).

321920040961 is an equidigital number, since it uses as much as digits as its factorization.

321920040961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6073963090.

The product of its (nonzero) digits is 23328, while the sum is 37.

The spelling of 321920040961 in words is "three hundred twenty-one billion, nine hundred twenty million, forty thousand, nine hundred sixty-one".