161905275 has 36 divisors (see below), whose sum is σ = 331420752. Its totient is φ = 74013120.

The previous prime is 161905273. The next prime is 161905279. The reversal of 161905275 is 572509161.

It is not a de Polignac number, because 161905275 - 2¹ = 161905273 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161905273) 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 35 ways as a sum of consecutive naturals, for example, 49824 + ... + 52973.

It is an arithmetic number, because the mean of its divisors is an integer number (9206132).

Almost surely, 2^161905275 is an apocalyptic number.

161905275 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

161905275 is an abundant number, since it is smaller than the sum of its proper divisors (169515477).

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

161905275 is a wasteful number, since it uses less digits than its factorization.

161905275 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102820 (or 102812 counting only the distinct ones).

The product of its (nonzero) digits is 18900, while the sum is 36.

The square root of 161905275 is about 12724.2003678031. The cubic root of 161905275 is about 545.0299060547.

The spelling of 161905275 in words is "one hundred sixty-one million, nine hundred five thousand, two hundred seventy-five".