221312630 has 192 divisors, whose sum is σ = 558472320. Its totient is φ = 61501440.

The previous prime is 221312617. The next prime is 221312633. The reversal of 221312630 is 36213122.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221312633) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4175684 + ... + 4175736.

It is an arithmetic number, because the mean of its divisors is an integer number (2908710).

Almost surely, 2^221312630 is an apocalyptic number.

221312630 is an abundant number, since it is smaller than the sum of its proper divisors (337159690).

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

221312630 is a wasteful number, since it uses less digits than its factorization.

221312630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135 (or 124 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 221312630 is about 14876.5799160963. The cubic root of 221312630 is about 604.8793147703.

Adding to 221312630 its reverse (36213122), we get a palindrome (257525752).

The spelling of 221312630 in words is "two hundred twenty-one million, three hundred twelve thousand, six hundred thirty".