13221620 has 24 divisors (see below), whose sum is σ = 28159488. Its totient is φ = 5213600.

The previous prime is 13221599. The next prime is 13221623. The reversal of 13221620 is 2612231.

It is a super-2 number, since 2×13221620² = 349622470848800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13221623) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3236 + ... + 6075.

It is an arithmetic number, because the mean of its divisors is an integer number (1173312).

Almost surely, 2^13221620 is an apocalyptic number.

13221620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13221620 is an abundant number, since it is smaller than the sum of its proper divisors (14937868).

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

13221620 is a wasteful number, since it uses less digits than its factorization.

13221620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9391 (or 9389 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 13221620 is about 3636.1545621714. The cubic root of 13221620 is about 236.4621080644.

Adding to 13221620 its reverse (2612231), we get a palindrome (15833851).

The spelling of 13221620 in words is "thirteen million, two hundred twenty-one thousand, six hundred twenty".