13221000 has 192 divisors, whose sum is σ = 48550320. Its totient is φ = 3225600.

The previous prime is 13220993. The next prime is 13221007. The reversal of 13221000 is 12231.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (13220993) and next prime (13221007).

It can be written as a sum of positive squares in 8 ways, for example, as 1483524 + 11737476 = 1218^2 + 3426^2 .

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (13221007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 116944 + ... + 117056.

Almost surely, 2^13221000 is an apocalyptic number.

13221000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13221000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24275160).

13221000 is an abundant number, since it is smaller than the sum of its proper divisors (35329320).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13221000 is a wasteful number, since it uses less digits than its factorization.

13221000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153 (or 136 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 13221000 is about 3636.0693062702. The cubic root of 13221000 is about 236.4584118759.

Adding to 13221000 its reverse (12231), we get a palindrome (13233231).

The spelling of 13221000 in words is "thirteen million, two hundred twenty-one thousand".