161945790 has 32 divisors (see below), whose sum is σ = 389918880. Its totient is φ = 43046784.

The previous prime is 161945743. The next prime is 161945803. The reversal of 161945790 is 97549161.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 996 + ... + 18024.

It is an arithmetic number, because the mean of its divisors is an integer number (12184965).

Almost surely, 2^161945790 is an apocalyptic number.

161945790 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

161945790 is an abundant number, since it is smaller than the sum of its proper divisors (227973090).

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

161945790 is a wasteful number, since it uses less digits than its factorization.

161945790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17356.

The product of its (nonzero) digits is 68040, while the sum is 42.

The square root of 161945790 is about 12725.7923132511. The cubic root of 161945790 is about 545.0753648268.

It can be divided in two parts, 161945 and 790, that added together give a triangular number (162735 = T₅₇₀).

The spelling of 161945790 in words is "one hundred sixty-one million, nine hundred forty-five thousand, seven hundred ninety".