645814869 has 16 divisors (see below), whose sum is σ = 1000233600. Its totient is φ = 362986560.

The previous prime is 645814859. The next prime is 645814877. The reversal of 645814869 is 968418546.

It is not a de Polignac number, because 645814869 - 2¹¹ = 645812821 is a prime.

It is a super-2 number, since 2×645814869² = 834153690042974322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645814859) 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, 250794 + ... + 253355.

It is an arithmetic number, because the mean of its divisors is an integer number (62514600).

Almost surely, 2^645814869 is an apocalyptic number.

It is an amenable number.

645814869 is a deficient number, since it is larger than the sum of its proper divisors (354418731).

645814869 is a wasteful number, since it uses less digits than its factorization.

645814869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 504220.

The product of its digits is 1658880, while the sum is 51.

The square root of 645814869 is about 25412.8878524264. The cubic root of 645814869 is about 864.3759602988.

The spelling of 645814869 in words is "six hundred forty-five million, eight hundred fourteen thousand, eight hundred sixty-nine".