645510347 has 4 divisors (see below), whose sum is σ = 647892576. Its totient is φ = 643128120.

The previous prime is 645510323. The next prime is 645510377. The reversal of 645510347 is 743015546.

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 645510347 - 2¹⁸ = 645248203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645510377) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1190708 + ... + 1191249.

It is an arithmetic number, because the mean of its divisors is an integer number (161973144).

Almost surely, 2^645510347 is an apocalyptic number.

645510347 is a deficient number, since it is larger than the sum of its proper divisors (2382229).

645510347 is a wasteful number, since it uses less digits than its factorization.

645510347 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2382228.

The product of its (nonzero) digits is 50400, while the sum is 35.

The square root of 645510347 is about 25406.8956584625. The cubic root of 645510347 is about 864.2400787988.

The spelling of 645510347 in words is "six hundred forty-five million, five hundred ten thousand, three hundred forty-seven".