3636603661 has 4 divisors (see below), whose sum is σ = 3636732924. Its totient is φ = 3636474400.

The previous prime is 3636603647. The next prime is 3636603679. The reversal of 3636603661 is 1663066363.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 2332310436 + 1304293225 = 48294^2 + 36115^2 .

It is a cyclic number.

It is not a de Polignac number, because 3636603661 - 2¹¹ = 3636601613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3636603631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2560 + ... + 85321.

It is an arithmetic number, because the mean of its divisors is an integer number (909183231).

Almost surely, 2^3636603661 is an apocalyptic number.

It is an amenable number.

3636603661 is a deficient number, since it is larger than the sum of its proper divisors (129263).

3636603661 is an equidigital number, since it uses as much as digits as its factorization.

3636603661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129262.

The product of its (nonzero) digits is 209952, while the sum is 40.

The square root of 3636603661 is about 60304.2590618606. The cubic root of 3636603661 is about 1537.7957531479.

The spelling of 3636603661 in words is "three billion, six hundred thirty-six million, six hundred three thousand, six hundred sixty-one".