645161 has 8 divisors (see below), whose sum is σ = 712800. Its totient is φ = 579040.

The previous prime is 645149. The next prime is 645179. The reversal of 645161 is 161546.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 645161 - 2⁶ = 645097 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 650 + ... + 1308.

It is an arithmetic number, because the mean of its divisors is an integer number (89100).

2⁶⁴⁵¹⁶¹ is an apocalyptic number.

It is an amenable number.

645161 is a deficient number, since it is larger than the sum of its proper divisors (67639).

645161 is a wasteful number, since it uses less digits than its factorization.

645161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 759.

The product of its digits is 720, while the sum is 23.

The square root of 645161 is about 803.2191481781. The cubic root of 645161 is about 86.4084143183.

It can be divided in two parts, 64 and 5161, that added together give a palindrome (5225).

The spelling of 645161 in words is "six hundred forty-five thousand, one hundred sixty-one".