645914393 has 4 divisors (see below), whose sum is σ = 647866128. Its totient is φ = 643962660.

The previous prime is 645914363. The next prime is 645914447. The reversal of 645914393 is 393419546.

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.

It is a cyclic number.

It is not a de Polignac number, because 645914393 - 2¹⁶ = 645848857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645914333) 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, 975371 + ... + 976032.

It is an arithmetic number, because the mean of its divisors is an integer number (161966532).

Almost surely, 2^645914393 is an apocalyptic number.

It is an amenable number.

645914393 is a deficient number, since it is larger than the sum of its proper divisors (1951735).

645914393 is a wasteful number, since it uses less digits than its factorization.

645914393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1951734.

The product of its digits is 349920, while the sum is 44.

The square root of 645914393 is about 25414.8459172980. The cubic root of 645914393 is about 864.4203598827.

The spelling of 645914393 in words is "six hundred forty-five million, nine hundred fourteen thousand, three hundred ninety-three".