2391965356321 has 4 divisors (see below), whose sum is σ = 2456613068692. Its totient is φ = 2327317643952.

The previous prime is 2391965356307. The next prime is 2391965356331. The reversal of 2391965356321 is 1236535691932.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1764542946321 + 627422410000 = 1328361^2 + 792100^2 .

It is a cyclic number.

It is not a de Polignac number, because 2391965356321 - 2¹⁷ = 2391965225249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2391965356331) 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, 32323856130 + ... + 32323856203.

It is an arithmetic number, because the mean of its divisors is an integer number (614153267173).

Almost surely, 2^{2391965356321} is an apocalyptic number.

It is an amenable number.

2391965356321 is a deficient number, since it is larger than the sum of its proper divisors (64647712371).

2391965356321 is an equidigital number, since it uses as much as digits as its factorization.

2391965356321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64647712370.

The product of its digits is 7873200, while the sum is 55.

The spelling of 2391965356321 in words is "two trillion, three hundred ninety-one billion, nine hundred sixty-five million, three hundred fifty-six thousand, three hundred twenty-one".