12406640 has 20 divisors (see below), whose sum is σ = 28845624. Its totient is φ = 4962624.

The previous prime is 12406633. The next prime is 12406649. The reversal of 12406640 is 4660421.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12406649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77462 + ... + 77621.

Almost surely, 2^12406640 is an apocalyptic number.

12406640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12406640 is an abundant number, since it is smaller than the sum of its proper divisors (16438984).

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

12406640 is a wasteful number, since it uses less digits than its factorization.

12406640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155096 (or 155090 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 12406640 is about 3522.3060627947. The cubic root of 12406640 is about 231.5002122506.

The spelling of 12406640 in words is "twelve million, four hundred six thousand, six hundred forty".