161311240 has 16 divisors (see below), whose sum is σ = 362950380. Its totient is φ = 64524480.

The previous prime is 161311237. The next prime is 161311279. The reversal of 161311240 is 42113161.

It can be written as a sum of positive squares in 2 ways, for example, as 147428164 + 13883076 = 12142^2 + 3726^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2016351 + ... + 2016430.

Almost surely, 2^161311240 is an apocalyptic number.

161311240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161311240 is an abundant number, since it is smaller than the sum of its proper divisors (201639140).

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

161311240 is a wasteful number, since it uses less digits than its factorization.

161311240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4032792 (or 4032788 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 161311240 is about 12700.8361929441. The cubic root of 161311240 is about 544.3625124831.

It can be divided in two parts, 16131 and 1240, that added together give a palindrome (17371).

The spelling of 161311240 in words is "one hundred sixty-one million, three hundred eleven thousand, two hundred forty".