15668221 has 8 divisors (see below), whose sum is σ = 16426944. Its totient is φ = 14916000.

The previous prime is 15668197. The next prime is 15668243. The reversal of 15668221 is 12286651.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 15668221 - 2¹¹ = 15666173 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 (15668281) 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 7 ways as a sum of consecutive naturals, for example, 3721 + ... + 6721.

It is an arithmetic number, because the mean of its divisors is an integer number (2053368).

Almost surely, 2^15668221 is an apocalyptic number.

It is an amenable number.

15668221 is a deficient number, since it is larger than the sum of its proper divisors (758723).

15668221 is a wasteful number, since it uses less digits than its factorization.

15668221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3251.

The product of its digits is 5760, while the sum is 31.

The square root of 15668221 is about 3958.3103718632. The cubic root of 15668221 is about 250.2302997829.

The spelling of 15668221 in words is "fifteen million, six hundred sixty-eight thousand, two hundred twenty-one".