645327651 has 16 divisors (see below), whose sum is σ = 896829440. Its totient is φ = 412292160.

The previous prime is 645327649. The next prime is 645327679. The reversal of 645327651 is 156723546.

It is not a de Polignac number, because 645327651 - 2¹ = 645327649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645327611) 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 15 ways as a sum of consecutive naturals, for example, 24106 + ... + 43263.

It is an arithmetic number, because the mean of its divisors is an integer number (56051840).

Almost surely, 2^645327651 is an apocalyptic number.

645327651 is a deficient number, since it is larger than the sum of its proper divisors (251501789).

645327651 is a wasteful number, since it uses less digits than its factorization.

645327651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67506.

The product of its digits is 151200, while the sum is 39.

The square root of 645327651 is about 25403.3000021651. The cubic root of 645327651 is about 864.1585370623.

The spelling of 645327651 in words is "six hundred forty-five million, three hundred twenty-seven thousand, six hundred fifty-one".