12721920 has 72 divisors (see below), whose sum is σ = 40642896. Its totient is φ = 3391488.

The previous prime is 12721903. The next prime is 12721939. The reversal of 12721920 is 2912721.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2184 + ... + 5496.

Almost surely, 2^12721920 is an apocalyptic number.

12721920 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 12721920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20321448).

12721920 is an abundant number, since it is smaller than the sum of its proper divisors (27920976).

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

12721920 is an equidigital number, since it uses as much as digits as its factorization.

12721920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3337 (or 3323 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 24.

The square root of 12721920 is about 3566.7800605027. The cubic root of 12721920 is about 233.4448084123. Note that the first 3 decimals are identical.

The spelling of 12721920 in words is "twelve million, seven hundred twenty-one thousand, nine hundred twenty".