645886571 has 16 divisors (see below), whose sum is σ = 724012128. Its totient is φ = 571084800.

The previous prime is 645886547. The next prime is 645886597. The reversal of 645886571 is 175688546.

It is not a de Polignac number, because 645886571 - 2¹⁰ = 645885547 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645889571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 157175 + ... + 161231.

It is an arithmetic number, because the mean of its divisors is an integer number (45250758).

Almost surely, 2^645886571 is an apocalyptic number.

645886571 is a deficient number, since it is larger than the sum of its proper divisors (78125557).

645886571 is a wasteful number, since it uses less digits than its factorization.

645886571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4462.

The product of its digits is 1612800, while the sum is 50.

The square root of 645886571 is about 25414.2985541604. The cubic root of 645886571 is about 864.4079484090.

The spelling of 645886571 in words is "six hundred forty-five million, eight hundred eighty-six thousand, five hundred seventy-one".