12391940 has 96 divisors (see below), whose sum is σ = 30965760. Its totient is φ = 4118400.

The previous prime is 12391937. The next prime is 12391987. The reversal of 12391940 is 4919321.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 156821 + ... + 156899.

It is an arithmetic number, because the mean of its divisors is an integer number (322560).

Almost surely, 2^12391940 is an apocalyptic number.

12391940 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 12391940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15482880).

12391940 is an abundant number, since it is smaller than the sum of its proper divisors (18573820).

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

12391940 is a wasteful number, since it uses less digits than its factorization.

12391940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153 (or 151 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 12391940 is about 3520.2187432033. The cubic root of 12391940 is about 231.4087451534.

It can be divided in two parts, 12391 and 940, that added together give a palindrome (13331).

The spelling of 12391940 in words is "twelve million, three hundred ninety-one thousand, nine hundred forty".