161207775 has 18 divisors (see below), whose sum is σ = 288741440. Its totient is φ = 85977360.

The previous prime is 161207771. The next prime is 161207789. The reversal of 161207775 is 577702161.

It is not a de Polignac number, because 161207775 - 2² = 161207771 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161207771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 358015 + ... + 358464.

Almost surely, 2^161207775 is an apocalyptic number.

161207775 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

161207775 is a deficient number, since it is larger than the sum of its proper divisors (127533665).

161207775 is a wasteful number, since it uses less digits than its factorization.

161207775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 716495 (or 716487 counting only the distinct ones).

The product of its (nonzero) digits is 20580, while the sum is 36.

The square root of 161207775 is about 12696.7623825919. The cubic root of 161207775 is about 544.2461029190.

It can be divided in two parts, 161 and 207775, that added together give a square (207936 = 456²).

The spelling of 161207775 in words is "one hundred sixty-one million, two hundred seven thousand, seven hundred seventy-five".