12291840 has 216 divisors, whose sum is σ = 46873008. Its totient is φ = 2949120.

The previous prime is 12291827. The next prime is 12291857. The reversal of 12291840 is 4819221.

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 23 ways as a sum of consecutive naturals, for example, 126672 + ... + 126768.

Almost surely, 2^12291840 is an apocalyptic number.

12291840 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 12291840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23436504).

12291840 is an abundant number, since it is smaller than the sum of its proper divisors (34581168).

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

12291840 is a wasteful number, since it uses less digits than its factorization.

12291840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 12291840 is about 3505.9720478064. The cubic root of 12291840 is about 230.7839662386.

It can be divided in two parts, 12291 and 840, that added together give a palindrome (13131).

The spelling of 12291840 in words is "twelve million, two hundred ninety-one thousand, eight hundred forty".