635666666536 has 64 divisors (see below), whose sum is σ = 1369397764800. Its totient is φ = 273584563200.

The previous prime is 635666666521. The next prime is 635666666539.

It is a happy number.

635666666536 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×635666666536² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (635666666539) 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, 3030166 + ... + 3233146.

It is an arithmetic number, because the mean of its divisors is an integer number (21396840075).

Almost surely, 2^635666666536 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 635666666536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (684698882400).

635666666536 is an abundant number, since it is smaller than the sum of its proper divisors (733731098264).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

635666666536 is a wasteful number, since it uses less digits than its factorization.

635666666536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204890 (or 204886 counting only the distinct ones).

The product of its digits is 377913600, while the sum is 64.

The spelling of 635666666536 in words is "six hundred thirty-five billion, six hundred sixty-six million, six hundred sixty-six thousand, five hundred thirty-six".