13221990 has 48 divisors (see below), whose sum is σ = 34723728. Its totient is φ = 3490368.

The previous prime is 13221977. The next prime is 13221997. The reversal of 13221990 is 9912231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13221997) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8944 + ... + 10316.

It is an arithmetic number, because the mean of its divisors is an integer number (723411).

Almost surely, 2^13221990 is an apocalyptic number.

13221990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 13221990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17361864).

13221990 is an abundant number, since it is smaller than the sum of its proper divisors (21501738).

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

13221990 is a wasteful number, since it uses less digits than its factorization.

13221990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1493 (or 1490 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 13221990 is about 3636.2054397407. The cubic root of 13221990 is about 236.4643137992.

It can be divided in two parts, 132 and 21990, that added together give a palindrome (22122).

The spelling of 13221990 in words is "thirteen million, two hundred twenty-one thousand, nine hundred ninety".