221317730 has 64 divisors (see below), whose sum is σ = 445098240. Its totient is φ = 78952192.

The previous prime is 221317729. The next prime is 221317739. The reversal of 221317730 is 37713122.

It is a super-2 number, since 2×221317730² = 97963075224705800, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 221317730.

It is not an unprimeable number, because it can be changed into a prime (221317739) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 2068337 + ... + 2068443.

It is an arithmetic number, because the mean of its divisors is an integer number (6954660).

Almost surely, 2^221317730 is an apocalyptic number.

221317730 is an abundant number, since it is smaller than the sum of its proper divisors (223780510).

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

221317730 is a wasteful number, since it uses less digits than its factorization.

221317730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200 (or 154 counting only the distinct ones).

The product of its (nonzero) digits is 1764, while the sum is 26.

The square root of 221317730 is about 14876.7513254743. The cubic root of 221317730 is about 604.8839610796.

The spelling of 221317730 in words is "two hundred twenty-one million, three hundred seventeen thousand, seven hundred thirty".