645073 has 12 divisors (see below), whose sum is σ = 764208. Its totient is φ = 539760.

The previous prime is 645067. The next prime is 645077. The reversal of 645073 is 370546.

It is not a de Polignac number, because 645073 - 2⁵ = 645041 is a prime.

It is a super-2 number, since 2×645073² = 832238350658, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645077) 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, 1686 + ... + 2032.

It is an arithmetic number, because the mean of its divisors is an integer number (63684).

2⁶⁴⁵⁰⁷³ is an apocalyptic number.

It is an amenable number.

645073 is a deficient number, since it is larger than the sum of its proper divisors (119135).

645073 is a wasteful number, since it uses less digits than its factorization.

645073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384 (or 371 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 25.

The square root of 645073 is about 803.1643667395. The cubic root of 645073 is about 86.4044854353.

The spelling of 645073 in words is "six hundred forty-five thousand, seventy-three".