645734365 has 4 divisors (see below), whose sum is σ = 774881244. Its totient is φ = 516587488.

The previous prime is 645734359. The next prime is 645734413. The reversal of 645734365 is 563437546.

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

It can be written as a sum of positive squares in 2 ways, for example, as 167262489 + 478471876 = 12933^2 + 21874^2 .

It is a cyclic number.

It is not a de Polignac number, because 645734365 - 2³ = 645734357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64573432 + ... + 64573441.

It is an arithmetic number, because the mean of its divisors is an integer number (193720311).

Almost surely, 2^645734365 is an apocalyptic number.

It is an amenable number.

645734365 is a deficient number, since it is larger than the sum of its proper divisors (129146879).

645734365 is a wasteful number, since it uses less digits than its factorization.

645734365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129146878.

The product of its digits is 907200, while the sum is 43.

The square root of 645734365 is about 25411.3038823276. The cubic root of 645734365 is about 864.3400425680.

The spelling of 645734365 in words is "six hundred forty-five million, seven hundred thirty-four thousand, three hundred sixty-five".