12704640 has 128 divisors (see below), whose sum is σ = 43696800. Its totient is φ = 3121152.

The previous prime is 12704633. The next prime is 12704641. The reversal of 12704640 is 4640721.

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

It is a super-2 number, since 2×12704640² = 322815755059200, which contains 22 as substring.

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 12704640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12704641) 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, 24706 + ... + 25214.

Almost surely, 2^12704640 is an apocalyptic number.

12704640 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 12704640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21848400).

12704640 is an abundant number, since it is smaller than the sum of its proper divisors (30992160).

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

12704640 is a wasteful number, since it uses less digits than its factorization.

12704640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 544 (or 532 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 12704640 is about 3564.3568844884. The cubic root of 12704640 is about 233.3390656188.

The spelling of 12704640 in words is "twelve million, seven hundred four thousand, six hundred forty".