161161956 has 72 divisors (see below), whose sum is σ = 415167480. Its totient is φ = 52706304.

The previous prime is 161161907. The next prime is 161161969. The reversal of 161161956 is 659161161.

161161956 = T₇₃ + T₇₄ + ... + T₉₈₈.

It can be written as a sum of positive squares in 4 ways, for example, as 46457856 + 114704100 = 6816^2 + 10710^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 161161956.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 703650 + ... + 703878.

It is an arithmetic number, because the mean of its divisors is an integer number (5766215).

Almost surely, 2^161161956 is an apocalyptic number.

It is an amenable number.

161161956 is an abundant number, since it is smaller than the sum of its proper divisors (254005524).

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

161161956 is a wasteful number, since it uses less digits than its factorization.

161161956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525 (or 520 counting only the distinct ones).

The product of its digits is 9720, while the sum is 36.

The square root of 161161956 is about 12694.9578967399. The cubic root of 161161956 is about 544.1945355652.

The spelling of 161161956 in words is "one hundred sixty-one million, one hundred sixty-one thousand, nine hundred fifty-six".