12781920 has 96 divisors (see below), whose sum is σ = 41610240. Its totient is φ = 3294720.

The previous prime is 12781919. The next prime is 12781931. The reversal of 12781920 is 2918721.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14451 + ... + 15309.

It is an arithmetic number, because the mean of its divisors is an integer number (433440).

Almost surely, 2^12781920 is an apocalyptic number.

12781920 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 12781920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20805120).

12781920 is an abundant number, since it is smaller than the sum of its proper divisors (28828320).

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

12781920 is a wasteful number, since it uses less digits than its factorization.

12781920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 908 (or 900 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 12781920 is about 3575.1811142934. The cubic root of 12781920 is about 233.8112291582.

The spelling of 12781920 in words is "twelve million, seven hundred eighty-one thousand, nine hundred twenty".