165821428793 has 2 divisors, whose sum is σ = 165821428794. Its totient is φ = 165821428792.

The previous prime is 165821428783. The next prime is 165821428831. The reversal of 165821428793 is 397824128561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 148777604089 + 17043824704 = 385717^2 + 130552^2 .

It is an emirp because it is prime and its reverse (397824128561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 165821428793 - 2⁸ = 165821428537 is a prime.

It is not a weakly prime, because it can be changed into another prime (165821428783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82910714396 + 82910714397.

It is an arithmetic number, because the mean of its divisors is an integer number (82910714397).

Almost surely, 2^165821428793 is an apocalyptic number.

It is an amenable number.

165821428793 is a deficient number, since it is larger than the sum of its proper divisors (1).

165821428793 is an equidigital number, since it uses as much as digits as its factorization.

165821428793 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5806080, while the sum is 56.

The spelling of 165821428793 in words is "one hundred sixty-five billion, eight hundred twenty-one million, four hundred twenty-eight thousand, seven hundred ninety-three".