645430337 has 4 divisors (see below), whose sum is σ = 652084356. Its totient is φ = 638776320.

The previous prime is 645430321. The next prime is 645430369. The reversal of 645430337 is 733034546.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 733034546 = 2 ⋅366517273.

It can be written as a sum of positive squares in 2 ways, for example, as 144744961 + 500685376 = 12031^2 + 22376^2 .

It is a cyclic number.

It is not a de Polignac number, because 645430337 - 2⁴ = 645430321 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 645430297 and 645430306.

It is not an unprimeable number, because it can be changed into a prime (645430307) 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, 3326864 + ... + 3327057.

It is an arithmetic number, because the mean of its divisors is an integer number (163021089).

Almost surely, 2^645430337 is an apocalyptic number.

It is an amenable number.

645430337 is a deficient number, since it is larger than the sum of its proper divisors (6654019).

645430337 is an equidigital number, since it uses as much as digits as its factorization.

645430337 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6654018.

The product of its (nonzero) digits is 90720, while the sum is 35.

The square root of 645430337 is about 25405.3210371371. The cubic root of 645430337 is about 864.2043702538.

The spelling of 645430337 in words is "six hundred forty-five million, four hundred thirty thousand, three hundred thirty-seven".