1636727645 has 12 divisors (see below), whose sum is σ = 2284738524. Its totient is φ = 1122327360.

The previous prime is 1636727579. The next prime is 1636727647. The reversal of 1636727645 is 5467276361.

It can be written as a sum of positive squares in 2 ways, for example, as 664659961 + 972067684 = 25781^2 + 31178^2 .

It is not a de Polignac number, because 1636727645 - 2²⁰ = 1635679069 is a prime.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1636727645.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1636727647) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3340016 + ... + 3340505.

It is an arithmetic number, because the mean of its divisors is an integer number (190394877).

Almost surely, 2^1636727645 is an apocalyptic number.

It is an amenable number.

1636727645 is a deficient number, since it is larger than the sum of its proper divisors (648010879).

1636727645 is an equidigital number, since it uses as much as digits as its factorization.

1636727645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6680540 (or 6680533 counting only the distinct ones).

The product of its digits is 1270080, while the sum is 47.

The square root of 1636727645 is about 40456.4907647710. The cubic root of 1636727645 is about 1178.4888356901.

The spelling of 1636727645 in words is "one billion, six hundred thirty-six million, seven hundred twenty-seven thousand, six hundred forty-five".