645735 has 8 divisors (see below), whose sum is σ = 1033200. Its totient is φ = 344384.

The previous prime is 645727. The next prime is 645737. The reversal of 645735 is 537546.

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

It is a cyclic number.

It is not a de Polignac number, because 645735 - 2³ = 645727 is a prime.

It is an Ulam number.

645735 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645737) 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, 21510 + ... + 21539.

It is an arithmetic number, because the mean of its divisors is an integer number (129150).

2⁶⁴⁵⁷³⁵ is an apocalyptic number.

645735 is a deficient number, since it is larger than the sum of its proper divisors (387465).

645735 is a wasteful number, since it uses less digits than its factorization.

645735 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43057.

The product of its digits is 12600, while the sum is 30.

The square root of 645735 is about 803.5763809371. The cubic root of 645735 is about 86.4340325892.

The spelling of 645735 in words is "six hundred forty-five thousand, seven hundred thirty-five".