221000632636 has 24 divisors (see below), whose sum is σ = 465264490880. Its totient is φ = 89729579952.

The previous prime is 221000632631. The next prime is 221000632661. The reversal of 221000632636 is 636236000122.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 221000632598 and 221000632607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221000632631) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 207706830 + ... + 207707893.

Almost surely, 2^221000632636 is an apocalyptic number.

It is an amenable number.

221000632636 is an abundant number, since it is smaller than the sum of its proper divisors (244263858244).

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

221000632636 is a wasteful number, since it uses less digits than its factorization.

221000632636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 415414753 (or 415414751 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 31.

Adding to 221000632636 its reverse (636236000122), we get a palindrome (857236632758).

The spelling of 221000632636 in words is "two hundred twenty-one billion, six hundred thirty-two thousand, six hundred thirty-six".