221512120 has 32 divisors (see below), whose sum is σ = 498849120. Its totient is φ = 88525440.

The previous prime is 221512099. The next prime is 221512133. The reversal of 221512120 is 21215122.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 221512094 and 221512103.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66085 + ... + 69355.

It is an arithmetic number, because the mean of its divisors is an integer number (15589035).

Almost surely, 2^221512120 is an apocalyptic number.

221512120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221512120 is an abundant number, since it is smaller than the sum of its proper divisors (277337000).

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

221512120 is a wasteful number, since it uses less digits than its factorization.

221512120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4975 (or 4971 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 221512120 is about 14883.2832399306. The cubic root of 221512120 is about 605.0610051636.

Adding to 221512120 its reverse (21215122), we get a palindrome (242727242).

The spelling of 221512120 in words is "two hundred twenty-one million, five hundred twelve thousand, one hundred twenty".