645436161 has 32 divisors (see below), whose sum is σ = 1014768000. Its totient is φ = 404052480.

The previous prime is 645436159. The next prime is 645436171. The reversal of 645436161 is 161634546.

It is a happy number.

645436161 is a `hidden beast` number, since 64 + 5 + 436 + 161 = 666.

It is not a de Polignac number, because 645436161 - 2¹ = 645436159 is a prime.

Its product of digits (51840) is a multiple of the sum of its prime divisors (3240).

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (645436171) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 237790 + ... + 240488.

It is an arithmetic number, because the mean of its divisors is an integer number (31711500).

Almost surely, 2^645436161 is an apocalyptic number.

It is an amenable number.

645436161 is a deficient number, since it is larger than the sum of its proper divisors (369331839).

645436161 is a wasteful number, since it uses less digits than its factorization.

645436161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3246 (or 3240 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 645436161 is about 25405.4356585358. The cubic root of 645436161 is about 864.2069696105.

The spelling of 645436161 in words is "six hundred forty-five million, four hundred thirty-six thousand, one hundred sixty-one".