3644436385 has 4 divisors (see below), whose sum is σ = 4373323668. Its totient is φ = 2915549104.

The previous prime is 3644436377. The next prime is 3644436401. The reversal of 3644436385 is 5836344463.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1211875344 + 2432561041 = 34812^2 + 49321^2 .

It is a cyclic number.

It is not a de Polignac number, because 3644436385 - 2³ = 3644436377 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 364443634 + ... + 364443643.

It is an arithmetic number, because the mean of its divisors is an integer number (1093330917).

Almost surely, 2^3644436385 is an apocalyptic number.

It is an amenable number.

3644436385 is a deficient number, since it is larger than the sum of its proper divisors (728887283).

3644436385 is an equidigital number, since it uses as much as digits as its factorization.

3644436385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 728887282.

The product of its digits is 2488320, while the sum is 46.

The square root of 3644436385 is about 60369.1675029563. The cubic root of 3644436385 is about 1538.8990254434.

The spelling of 3644436385 in words is "three billion, six hundred forty-four million, four hundred thirty-six thousand, three hundred eighty-five".