161790 has 16 divisors (see below), whose sum is σ = 388368. Its totient is φ = 43136.

The previous prime is 161783. The next prime is 161807. The reversal of 161790 is 97161.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 161790.

It is a congruent number.

It is an unprimeable number.

161790 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2667 + ... + 2726.

It is an arithmetic number, because the mean of its divisors is an integer number (24273).

2¹⁶¹⁷⁹⁰ is an apocalyptic number.

161790 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

161790 is an abundant number, since it is smaller than the sum of its proper divisors (226578).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161790 is a wasteful number, since it uses less digits than its factorization.

161790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5403.

The product of its (nonzero) digits is 378, while the sum is 24.

The square root of 161790 is about 402.2312767551. The cubic root of 161790 is about 54.4900523325.

It can be divided in two parts, 1617 and 90, that multiplied together give a triangular number (145530 = T₅₃₉).

The spelling of 161790 in words is "one hundred sixty-one thousand, seven hundred ninety".