221221221607 has 4 divisors (see below), whose sum is σ = 221222643376. Its totient is φ = 221219799840.

The previous prime is 221221221601. The next prime is 221221221631. The reversal of 221221221607 is 706122122122.

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 221221221607 - 2⁷ = 221221221479 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221221221601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 444123 + ... + 799804.

It is an arithmetic number, because the mean of its divisors is an integer number (55305660844).

Almost surely, 2^221221221607 is an apocalyptic number.

221221221607 is a deficient number, since it is larger than the sum of its proper divisors (1421769).

221221221607 is a wasteful number, since it uses less digits than its factorization.

221221221607 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1421768.

The product of its (nonzero) digits is 2688, while the sum is 28.

Adding to 221221221607 its reverse (706122122122), we get a palindrome (927343343729).

The spelling of 221221221607 in words is "two hundred twenty-one billion, two hundred twenty-one million, two hundred twenty-one thousand, six hundred seven".