165578993 has 2 divisors, whose sum is σ = 165578994. Its totient is φ = 165578992.

The previous prime is 165578983. The next prime is 165578999. The reversal of 165578993 is 399875561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 88981489 + 76597504 = 9433^2 + 8752^2 .

It is a cyclic number.

It is not a de Polignac number, because 165578993 - 2¹⁰ = 165577969 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (165578999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82789496 + 82789497.

It is an arithmetic number, because the mean of its divisors is an integer number (82789497).

Almost surely, 2^165578993 is an apocalyptic number.

It is an amenable number.

165578993 is a deficient number, since it is larger than the sum of its proper divisors (1).

165578993 is an equidigital number, since it uses as much as digits as its factorization.

165578993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2041200, while the sum is 53.

The square root of 165578993 is about 12867.7501141419. The cubic root of 165578993 is about 549.1214546987.

The spelling of 165578993 in words is "one hundred sixty-five million, five hundred seventy-eight thousand, nine hundred ninety-three".