161942905 has 16 divisors (see below), whose sum is σ = 199117440. Its totient is φ = 126397312.

The previous prime is 161942897. The next prime is 161942927. The reversal of 161942905 is 509249161.

It is a cyclic number.

It is not a de Polignac number, because 161942905 - 2³ = 161942897 is a prime.

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, 38412 + ... + 42418.

It is an arithmetic number, because the mean of its divisors is an integer number (12444840).

Almost surely, 2^161942905 is an apocalyptic number.

It is an amenable number.

161942905 is a deficient number, since it is larger than the sum of its proper divisors (37174535).

161942905 is a wasteful number, since it uses less digits than its factorization.

161942905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4208.

The product of its (nonzero) digits is 19440, while the sum is 37.

The square root of 161942905 is about 12725.6789602756. The cubic root of 161942905 is about 545.0721280404.

The spelling of 161942905 in words is "one hundred sixty-one million, nine hundred forty-two thousand, nine hundred five".