13217920 has 64 divisors (see below), whose sum is σ = 33292800. Its totient is φ = 5004288.

The previous prime is 13217909. The next prime is 13217921. The reversal of 13217920 is 2971231.

13217920 = 325² + 326² + ... + 419².

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (13217921) 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, 11617 + ... + 12703.

It is an arithmetic number, because the mean of its divisors is an integer number (520200).

Almost surely, 2^13217920 is an apocalyptic number.

13217920 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 13217920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16646400).

13217920 is an abundant number, since it is smaller than the sum of its proper divisors (20074880).

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

13217920 is a wasteful number, since it uses less digits than its factorization.

13217920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1125 (or 1113 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 13217920 is about 3635.6457473192. The cubic root of 13217920 is about 236.4400484523.

The spelling of 13217920 in words is "thirteen million, two hundred seventeen thousand, nine hundred twenty".