165634993 has 2 divisors, whose sum is σ = 165634994. Its totient is φ = 165634992.

The previous prime is 165634991. The next prime is 165635053. The reversal of 165634993 is 399436561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 132319009 + 33315984 = 11503^2 + 5772^2 .

It is a cyclic number.

It is not a de Polignac number, because 165634993 - 2¹ = 165634991 is a prime.

It is a super-2 number, since 2×165634993² = 54869901812220098, which contains 22 as substring.

Together with 165634991, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (165634991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82817496 + 82817497.

It is an arithmetic number, because the mean of its divisors is an integer number (82817497).

Almost surely, 2^165634993 is an apocalyptic number.

It is an amenable number.

165634993 is a deficient number, since it is larger than the sum of its proper divisors (1).

165634993 is an equidigital number, since it uses as much as digits as its factorization.

165634993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 524880, while the sum is 46.

The square root of 165634993 is about 12869.9259127627. The cubic root of 165634993 is about 549.1833533225.

The spelling of 165634993 in words is "one hundred sixty-five million, six hundred thirty-four thousand, nine hundred ninety-three".