12278640 has 80 divisors (see below), whose sum is σ = 41533056. Its totient is φ = 2976000.

The previous prime is 12278633. The next prime is 12278647. The reversal of 12278640 is 4687221.

It is an interprime number because it is at equal distance from previous prime (12278633) and next prime (12278647).

It is a tau number, because it is divible by the number of its divisors (80).

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 = 12278598 and 12278607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12278647) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 315 + ... + 4965.

Almost surely, 2^12278640 is an apocalyptic number.

12278640 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 12278640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20766528).

12278640 is an abundant number, since it is smaller than the sum of its proper divisors (29254416).

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

12278640 is a wasteful number, since it uses less digits than its factorization.

12278640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4678 (or 4672 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 12278640 is about 3504.0890399646. The cubic root of 12278640 is about 230.7013249774.

The spelling of 12278640 in words is "twelve million, two hundred seventy-eight thousand, six hundred forty".