221116657 has 4 divisors (see below), whose sum is σ = 221486400. Its totient is φ = 220746916.

The previous prime is 221116639. The next prime is 221116667. The reversal of 221116657 is 756611122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221116657 - 2¹⁹ = 220592369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221116607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 183973 + ... + 185170.

It is an arithmetic number, because the mean of its divisors is an integer number (55371600).

Almost surely, 2^221116657 is an apocalyptic number.

It is an amenable number.

221116657 is a deficient number, since it is larger than the sum of its proper divisors (369743).

221116657 is an equidigital number, since it uses as much as digits as its factorization.

221116657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 369742.

The product of its digits is 5040, while the sum is 31.

The square root of 221116657 is about 14869.9918291840. The cubic root of 221116657 is about 604.7007212269.

Adding to 221116657 its reverse (756611122), we get a palindrome (977727779).

The spelling of 221116657 in words is "two hundred twenty-one million, one hundred sixteen thousand, six hundred fifty-seven".