161399 has 4 divisors (see below), whose sum is σ = 184464. Its totient is φ = 138336.

The previous prime is 161387. The next prime is 161407. The reversal of 161399 is 993161.

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 161399 - 2¹² = 157303 is a prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 161399.

It is not an unprimeable number, because it can be changed into a prime (161309) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11522 + ... + 11535.

It is an arithmetic number, because the mean of its divisors is an integer number (46116).

2¹⁶¹³⁹⁹ is an apocalyptic number.

161399 is a deficient number, since it is larger than the sum of its proper divisors (23065).

161399 is an equidigital number, since it uses as much as digits as its factorization.

161399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23064.

The product of its digits is 1458, while the sum is 29.

The square root of 161399 is about 401.7449439632. The cubic root of 161399 is about 54.4461213175.

The spelling of 161399 in words is "one hundred sixty-one thousand, three hundred ninety-nine".