645701 has 4 divisors (see below), whose sum is σ = 737952. Its totient is φ = 553452.

The previous prime is 645691. The next prime is 645703. The reversal of 645701 is 107546.

645701 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 107546 = 2 ⋅53773.

It is a cyclic number.

It is not a de Polignac number, because 645701 - 2¹⁸ = 383557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645701.

It is not an unprimeable number, because it can be changed into a prime (645703) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46115 + ... + 46128.

It is an arithmetic number, because the mean of its divisors is an integer number (184488).

2⁶⁴⁵⁷⁰¹ is an apocalyptic number.

It is an amenable number.

645701 is a deficient number, since it is larger than the sum of its proper divisors (92251).

645701 is an equidigital number, since it uses as much as digits as its factorization.

645701 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92250.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 645701 is about 803.5552252335. Note that the first 3 decimals coincide. The cubic root of 645701 is about 86.4325155537.

The spelling of 645701 in words is "six hundred forty-five thousand, seven hundred one".