12191640 has 64 divisors (see below), whose sum is σ = 36806400. Its totient is φ = 3230592.

The previous prime is 12191593. The next prime is 12191651. The reversal of 12191640 is 4619121.

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

It is a self number, because there is not a number n which added to its sum of digits gives 12191640.

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, 33781 + ... + 34139.

It is an arithmetic number, because the mean of its divisors is an integer number (575100).

Almost surely, 2^12191640 is an apocalyptic number.

12191640 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 12191640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18403200).

12191640 is an abundant number, since it is smaller than the sum of its proper divisors (24614760).

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

12191640 is a wasteful number, since it uses less digits than its factorization.

12191640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 656 (or 652 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 12191640 is about 3491.6529037119. The cubic root of 12191640 is about 230.1551568082.

The spelling of 12191640 in words is "twelve million, one hundred ninety-one thousand, six hundred forty".