165961540 has 12 divisors (see below), whose sum is σ = 348519276. Its totient is φ = 66384608.

The previous prime is 165961489. The next prime is 165961573. The reversal of 165961540 is 45169561.

165961540 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 84492864 + 81468676 = 9192^2 + 9026^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 165961540.

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, 4149019 + ... + 4149058.

It is an arithmetic number, because the mean of its divisors is an integer number (29043273).

Almost surely, 2^165961540 is an apocalyptic number.

165961540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165961540 is an abundant number, since it is smaller than the sum of its proper divisors (182557736).

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

165961540 is a wasteful number, since it uses less digits than its factorization.

165961540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8298086 (or 8298084 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 37.

The square root of 165961540 is about 12882.6061028039. The cubic root of 165961540 is about 549.5440187643.

The spelling of 165961540 in words is "one hundred sixty-five million, nine hundred sixty-one thousand, five hundred forty".