645320383 has 4 divisors (see below), whose sum is σ = 667572840. Its totient is φ = 623067928.

The previous prime is 645320363. The next prime is 645320413. The reversal of 645320383 is 383023546.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 645320383 - 2²⁵ = 611765951 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645320303) 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, 11126185 + ... + 11126242.

It is an arithmetic number, because the mean of its divisors is an integer number (166893210).

Almost surely, 2^645320383 is an apocalyptic number.

645320383 is a deficient number, since it is larger than the sum of its proper divisors (22252457).

645320383 is a wasteful number, since it uses less digits than its factorization.

645320383 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22252456.

The product of its (nonzero) digits is 51840, while the sum is 34.

The square root of 645320383 is about 25403.1569494817. The cubic root of 645320383 is about 864.1552928562.

The spelling of 645320383 in words is "six hundred forty-five million, three hundred twenty thousand, three hundred eighty-three".