161642399 has 2 divisors, whose sum is σ = 161642400. Its totient is φ = 161642398.

The previous prime is 161642389. The next prime is 161642407. The reversal of 161642399 is 993246161.

It is a strong prime.

It is an emirp because it is prime and its reverse (993246161) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161642399 is a prime.

It is a super-2 number, since 2×161642399² = 52256530308950402, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161642309) 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, 80821199 + 80821200.

It is an arithmetic number, because the mean of its divisors is an integer number (80821200).

Almost surely, 2^161642399 is an apocalyptic number.

161642399 is a deficient number, since it is larger than the sum of its proper divisors (1).

161642399 is an equidigital number, since it uses as much as digits as its factorization.

161642399 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69984, while the sum is 41.

The square root of 161642399 is about 12713.8664064084. The cubic root of 161642399 is about 544.7347686786.

The spelling of 161642399 in words is "one hundred sixty-one million, six hundred forty-two thousand, three hundred ninety-nine".