12397440 has 128 divisors (see below), whose sum is σ = 43182720. Its totient is φ = 3000320.

The previous prime is 12397417. The next prime is 12397453. The reversal of 12397440 is 4479321.

It is a happy number.

It is a Cunningham number, because it is equal to 3521²-1.

It is a tau number, because it is divible by the number of its divisors (128).

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

It is a junction number, because it is equal to n+sod(n) for n = 12397398 and 12397407.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20827 + ... + 21413.

It is an arithmetic number, because the mean of its divisors is an integer number (337365).

Almost surely, 2^12397440 is an apocalyptic number.

12397440 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 12397440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21591360).

12397440 is an abundant number, since it is smaller than the sum of its proper divisors (30785280).

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

12397440 is a wasteful number, since it uses less digits than its factorization.

12397440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 620 (or 608 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 12397440 is about 3520.9998579949. Note that the first 3 decimals coincide. The cubic root of 12397440 is about 231.4429760015.

The spelling of 12397440 in words is "twelve million, three hundred ninety-seven thousand, four hundred forty".