161369999 has 4 divisors (see below), whose sum is σ = 184422864. Its totient is φ = 138317136.

The previous prime is 161369993. The next prime is 161370049. The reversal of 161369999 is 999963161.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 161369999 - 2⁸ = 161369743 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 161369999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161369993) 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 in 3 ways as a sum of consecutive naturals, for example, 11526422 + ... + 11526435.

It is an arithmetic number, because the mean of its divisors is an integer number (46105716).

Almost surely, 2^161369999 is an apocalyptic number.

161369999 is a deficient number, since it is larger than the sum of its proper divisors (23052865).

161369999 is an equidigital number, since it uses as much as digits as its factorization.

161369999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23052864.

The product of its digits is 708588, while the sum is 53.

The square root of 161369999 is about 12703.1491764838. The cubic root of 161369999 is about 544.4286006943.

The spelling of 161369999 in words is "one hundred sixty-one million, three hundred sixty-nine thousand, nine hundred ninety-nine".