161264565 has 72 divisors (see below), whose sum is σ = 351222144. Its totient is φ = 67003200.

The previous prime is 161264561. The next prime is 161264581. The reversal of 161264565 is 565462161.

161264565 is a `hidden beast` number, since 1 + 6 + 1 + 2 + 645 + 6 + 5 = 666.

It is not a de Polignac number, because 161264565 - 2² = 161264561 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161264561) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 36000 + ... + 40230.

Almost surely, 2^161264565 is an apocalyptic number.

161264565 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161264565 is an abundant number, since it is smaller than the sum of its proper divisors (189957579).

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

161264565 is a wasteful number, since it uses less digits than its factorization.

161264565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4271 (or 4257 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 161264565 is about 12698.9985825655. The cubic root of 161264565 is about 544.3100041122.

Adding to 161264565 its sum of digits (36), we get a square (161264601 = 12699²).

The spelling of 161264565 in words is "one hundred sixty-one million, two hundred sixty-four thousand, five hundred sixty-five".