636288433661 has 16 divisors (see below), whose sum is σ = 665346700800. Its totient is φ = 607346982528.

The previous prime is 636288433643. The next prime is 636288433663. The reversal of 636288433661 is 166334882636.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-636288433661 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 636288433597 and 636288433606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (636288433663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62627900 + ... + 62638058.

It is an arithmetic number, because the mean of its divisors is an integer number (41584168800).

Almost surely, 2^636288433661 is an apocalyptic number.

It is an amenable number.

636288433661 is a deficient number, since it is larger than the sum of its proper divisors (29058267139).

636288433661 is a wasteful number, since it uses less digits than its factorization.

636288433661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15628.

The product of its digits is 17915904, while the sum is 56.

The spelling of 636288433661 in words is "six hundred thirty-six billion, two hundred eighty-eight million, four hundred thirty-three thousand, six hundred sixty-one".