221221630 has 16 divisors (see below), whose sum is σ = 455084640. Its totient is φ = 75847392.

The previous prime is 221221619. The next prime is 221221633. The reversal of 221221630 is 36122122.

It is a junction number, because it is equal to n+sod(n) for n = 221221598 and 221221607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221221633) 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, 1580085 + ... + 1580224.

It is an arithmetic number, because the mean of its divisors is an integer number (28442790).

Almost surely, 2^221221630 is an apocalyptic number.

221221630 is an abundant number, since it is smaller than the sum of its proper divisors (233863010).

221221630 is a wasteful number, since it uses less digits than its factorization.

221221630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3160323.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 221221630 is about 14873.5211029534. The cubic root of 221221630 is about 604.7963980328.

Adding to 221221630 its reverse (36122122), we get a palindrome (257343752).

The spelling of 221221630 in words is "two hundred twenty-one million, two hundred twenty-one thousand, six hundred thirty".