645897 has 8 divisors (see below), whose sum is σ = 984256. Its totient is φ = 369072.

The previous prime is 645893. The next prime is 645901. The reversal of 645897 is 798546.

645897 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (645893) and next prime (645901).

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

It is not a de Polignac number, because 645897 - 2² = 645893 is a prime.

645897 is a lucky number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645897.

It is not an unprimeable number, because it can be changed into a prime (645893) 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, 15358 + ... + 15399.

It is an arithmetic number, because the mean of its divisors is an integer number (123032).

2⁶⁴⁵⁸⁹⁷ is an apocalyptic number.

It is an amenable number.

645897 is a deficient number, since it is larger than the sum of its proper divisors (338359).

645897 is a wasteful number, since it uses less digits than its factorization.

645897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30767.

The product of its digits is 60480, while the sum is 39.

The square root of 645897 is about 803.6771739946. The cubic root of 645897 is about 86.4412600857.

It can be divided in two parts, 6458 and 97, that added together give a triangular number (6555 = T₁₁₄).

The spelling of 645897 in words is "six hundred forty-five thousand, eight hundred ninety-seven".