161756145 has 24 divisors (see below), whose sum is σ = 280890792. Its totient is φ = 86112000.

The previous prime is 161756137. The next prime is 161756149. The reversal of 161756145 is 541657161.

It is a happy number.

161756145 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 6305121 + 155451024 = 2511^2 + 12468^2 .

It is not a de Polignac number, because 161756145 - 2³ = 161756137 is a prime.

It is a super-2 number, since 2×161756145² = 52330100890522050, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161756149) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 24055 + ... + 30035.

It is an arithmetic number, because the mean of its divisors is an integer number (11703783).

Almost surely, 2^161756145 is an apocalyptic number.

161756145 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161756145 is a deficient number, since it is larger than the sum of its proper divisors (119134647).

161756145 is a wasteful number, since it uses less digits than its factorization.

161756145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6593 (or 6590 counting only the distinct ones).

The product of its digits is 25200, while the sum is 36.

The square root of 161756145 is about 12718.3389245609. The cubic root of 161756145 is about 544.8625133652.

The spelling of 161756145 in words is "one hundred sixty-one million, seven hundred fifty-six thousand, one hundred forty-five".