15221666 has 8 divisors (see below), whose sum is σ = 22850640. Its totient is φ = 7604788.

The previous prime is 15221639. The next prime is 15221669. The reversal of 15221666 is 66612251.

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

It is not an unprimeable number, because it can be changed into a prime (15221669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1445 + ... + 5703.

It is an arithmetic number, because the mean of its divisors is an integer number (2856330).

Almost surely, 2^15221666 is an apocalyptic number.

15221666 is a deficient number, since it is larger than the sum of its proper divisors (7628974).

15221666 is a wasteful number, since it uses less digits than its factorization.

15221666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6048.

The product of its digits is 4320, while the sum is 29.

The square root of 15221666 is about 3901.4953543481. The cubic root of 15221666 is about 247.8301060642.

The spelling of 15221666 in words is "fifteen million, two hundred twenty-one thousand, six hundred sixty-six".