161243775 has 144 divisors (see below), whose sum is σ = 370476288. Its totient is φ = 65088000.

The previous prime is 161243729. The next prime is 161243791. The reversal of 161243775 is 577342161.

It is a happy number.

161243775 is a `hidden beast` number, since 1 + 612 + 4 + 37 + 7 + 5 = 666.

It is not a de Polignac number, because 161243775 - 2⁷ = 161243647 is a prime.

Its product of digits (35280) is a multiple of the sum of its prime divisors (294).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 710212 + ... + 710438.

It is an arithmetic number, because the mean of its divisors is an integer number (2572752).

Almost surely, 2^161243775 is an apocalyptic number.

161243775 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

161243775 is an abundant number, since it is smaller than the sum of its proper divisors (209232513).

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

161243775 is a wasteful number, since it uses less digits than its factorization.

161243775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 302 (or 294 counting only the distinct ones).

The product of its digits is 35280, while the sum is 36.

The square root of 161243775 is about 12698.1799876990. The cubic root of 161243775 is about 544.2866125479.

The spelling of 161243775 in words is "one hundred sixty-one million, two hundred forty-three thousand, seven hundred seventy-five".