221421522 has 16 divisors (see below), whose sum is σ = 506106432. Its totient is φ = 63263280.

The previous prime is 221421517. The next prime is 221421539. The reversal of 221421522 is 225124122.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2635929 + ... + 2636012.

It is an arithmetic number, because the mean of its divisors is an integer number (31631652).

Almost surely, 2^221421522 is an apocalyptic number.

221421522 is an abundant number, since it is smaller than the sum of its proper divisors (284684910).

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

221421522 is a wasteful number, since it uses less digits than its factorization.

221421522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5271953.

The product of its digits is 640, while the sum is 21.

The square root of 221421522 is about 14880.2393125917. The cubic root of 221421522 is about 604.9785043475.

Adding to 221421522 its reverse (225124122), we get a palindrome (446545644).

The spelling of 221421522 in words is "two hundred twenty-one million, four hundred twenty-one thousand, five hundred twenty-two".