221655516 has 24 divisors (see below), whose sum is σ = 520920960. Its totient is φ = 73353072.

The previous prime is 221655491. The next prime is 221655523. The reversal of 221655516 is 615556122.

It is a super-3 number, since 3×221655516³ (a number of 26 digits) contains 333 as substring.

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, 64776 + ... + 68111.

It is an arithmetic number, because the mean of its divisors is an integer number (21705040).

Almost surely, 2^221655516 is an apocalyptic number.

It is an amenable number.

221655516 is an abundant number, since it is smaller than the sum of its proper divisors (299265444).

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

221655516 is a wasteful number, since it uses less digits than its factorization.

221655516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133033 (or 133031 counting only the distinct ones).

The product of its digits is 18000, while the sum is 33.

The square root of 221655516 is about 14888.0998115945. The cubic root of 221655516 is about 605.1915391987.

The spelling of 221655516 in words is "two hundred twenty-one million, six hundred fifty-five thousand, five hundred sixteen".