161265533 has 24 divisors (see below), whose sum is σ = 192404184. Its totient is φ = 134259840.

The previous prime is 161265529. The next prime is 161265547. The reversal of 161265533 is 335562161.

It can be written as a sum of positive squares in 4 ways, for example, as 407044 + 160858489 = 638^2 + 12683^2 .

It is not a de Polignac number, because 161265533 - 2² = 161265529 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 161265533.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161265563) 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, 246635 + ... + 247287.

It is an arithmetic number, because the mean of its divisors is an integer number (8016841).

Almost surely, 2^161265533 is an apocalyptic number.

161265533 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

161265533 is a deficient number, since it is larger than the sum of its proper divisors (31138651).

161265533 is a wasteful number, since it uses less digits than its factorization.

161265533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 845 (or 834 counting only the distinct ones).

The product of its digits is 16200, while the sum is 32.

The square root of 161265533 is about 12699.0366957498. The cubic root of 161265533 is about 544.3110931943.

The spelling of 161265533 in words is "one hundred sixty-one million, two hundred sixty-five thousand, five hundred thirty-three".