161665039 has 2 divisors, whose sum is σ = 161665040. Its totient is φ = 161665038.

The previous prime is 161665033. The next prime is 161665051. The reversal of 161665039 is 930566161.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 161665039 - 2¹⁹ = 161140751 is a prime.

It is a super-2 number, since 2×161665039² = 52271169669743042, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 161664989 and 161665007.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161665033) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80832519 + 80832520.

It is an arithmetic number, because the mean of its divisors is an integer number (80832520).

Almost surely, 2^161665039 is an apocalyptic number.

161665039 is a deficient number, since it is larger than the sum of its proper divisors (1).

161665039 is an equidigital number, since it uses as much as digits as its factorization.

161665039 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 29160, while the sum is 37.

The square root of 161665039 is about 12714.7567416762. The cubic root of 161665039 is about 544.7601997525.

The spelling of 161665039 in words is "one hundred sixty-one million, six hundred sixty-five thousand, thirty-nine".