13221766 has 4 divisors (see below), whose sum is σ = 19832652. Its totient is φ = 6610882.

The previous prime is 13221749. The next prime is 13221781. The reversal of 13221766 is 66712231.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 66712231 = 2161 ⋅30871.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3305440 + ... + 3305443.

It is an arithmetic number, because the mean of its divisors is an integer number (4958163).

Almost surely, 2^13221766 is an apocalyptic number.

13221766 is a deficient number, since it is larger than the sum of its proper divisors (6610886).

13221766 is an equidigital number, since it uses as much as digits as its factorization.

13221766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6610885.

The product of its digits is 3024, while the sum is 28.

The square root of 13221766 is about 3636.1746382703. The cubic root of 13221766 is about 236.4629784404.

Adding to 13221766 its reverse (66712231), we get a palindrome (79933997).

The spelling of 13221766 in words is "thirteen million, two hundred twenty-one thousand, seven hundred sixty-six".