645373161 has 12 divisors (see below), whose sum is σ = 939011892. Its totient is φ = 427107456.

The previous prime is 645373153. The next prime is 645373187. The reversal of 645373161 is 161373546.

645373161 is a `hidden beast` number, since 64 + 537 + 3 + 1 + 61 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 469545561 + 175827600 = 21669^2 + 13260^2 .

It is not a de Polignac number, because 645373161 - 2³ = 645373153 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (645373151) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 260476 + ... + 262941.

It is an arithmetic number, because the mean of its divisors is an integer number (78250991).

Almost surely, 2^645373161 is an apocalyptic number.

It is an amenable number.

645373161 is a deficient number, since it is larger than the sum of its proper divisors (293638731).

645373161 is a wasteful number, since it uses less digits than its factorization.

645373161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 523560 (or 523557 counting only the distinct ones).

The product of its digits is 45360, while the sum is 36.

The square root of 645373161 is about 25404.1957361378. The cubic root of 645373161 is about 864.1788507384.

The spelling of 645373161 in words is "six hundred forty-five million, three hundred seventy-three thousand, one hundred sixty-one".