221001320 has 32 divisors (see below), whose sum is σ = 498073320. Its totient is φ = 88254720.

The previous prime is 221001311. The next prime is 221001337. The reversal of 221001320 is 23100122.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 184253476 + 36747844 = 13574^2 + 6062^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21890 + ... + 30350.

Almost surely, 2^221001320 is an apocalyptic number.

221001320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221001320 is an abundant number, since it is smaller than the sum of its proper divisors (277072000).

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

221001320 is a wasteful number, since it uses less digits than its factorization.

221001320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9125 (or 9121 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 221001320 is about 14866.1131436566. The cubic root of 221001320 is about 604.5955633161.

Adding to 221001320 its reverse (23100122), we get a palindrome (244101442).

The spelling of 221001320 in words is "two hundred twenty-one million, one thousand, three hundred twenty".