221421340 has 24 divisors (see below), whose sum is σ = 531411552. Its totient is φ = 75915840.

The previous prime is 221421331. The next prime is 221421359. The reversal of 221421340 is 43124122.

It is a congruent number.

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, 790651 + ... + 790930.

It is an arithmetic number, because the mean of its divisors is an integer number (22142148).

Almost surely, 2^221421340 is an apocalyptic number.

221421340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221421340 is an abundant number, since it is smaller than the sum of its proper divisors (309990212).

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

221421340 is a wasteful number, since it uses less digits than its factorization.

221421340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1581597 (or 1581595 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 221421340 is about 14880.2331970974. The cubic root of 221421340 is about 604.9783385911.

Adding to 221421340 its reverse (43124122), we get a palindrome (264545462).

The spelling of 221421340 in words is "two hundred twenty-one million, four hundred twenty-one thousand, three hundred forty".