221216707 has 4 divisors (see below), whose sum is σ = 221278680. Its totient is φ = 221154736.

The previous prime is 221216701. The next prime is 221216731. The reversal of 221216707 is 707612122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 221216707 - 2⁷ = 221216579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221216701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25282 + ... + 32887.

It is an arithmetic number, because the mean of its divisors is an integer number (55319670).

Almost surely, 2^221216707 is an apocalyptic number.

221216707 is a deficient number, since it is larger than the sum of its proper divisors (61973).

221216707 is an equidigital number, since it uses as much as digits as its factorization.

221216707 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61972.

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 221216707 is about 14873.3556065872. The cubic root of 221216707 is about 604.7919116801.

Adding to 221216707 its reverse (707612122), we get a palindrome (928828829).

The spelling of 221216707 in words is "two hundred twenty-one million, two hundred sixteen thousand, seven hundred seven".