221631630 has 64 divisors (see below), whose sum is σ = 600307200. Its totient is φ = 51873920.

The previous prime is 221631629. The next prime is 221631643. The reversal of 221631630 is 36136122.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 221631630.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2010 + ... + 21149.

It is an arithmetic number, because the mean of its divisors is an integer number (9379800).

Almost surely, 2^221631630 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221631630, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (300153600).

221631630 is an abundant number, since it is smaller than the sum of its proper divisors (378675570).

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

221631630 is a wasteful number, since it uses less digits than its factorization.

221631630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23209.

The product of its (nonzero) digits is 1296, while the sum is 24.

The square root of 221631630 is about 14887.2976056771. The cubic root of 221631630 is about 605.1697995722.

Adding to 221631630 its reverse (36136122), we get a palindrome (257767752).

The spelling of 221631630 in words is "two hundred twenty-one million, six hundred thirty-one thousand, six hundred thirty".