12639840 has 96 divisors (see below), whose sum is σ = 42184800. Its totient is φ = 3170304.

The previous prime is 12639839. The next prime is 12639881. The reversal of 12639840 is 4893621.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7386 + ... + 8934.

It is an arithmetic number, because the mean of its divisors is an integer number (439425).

Almost surely, 2^12639840 is an apocalyptic number.

12639840 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 12639840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21092400).

12639840 is an abundant number, since it is smaller than the sum of its proper divisors (29544960).

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

12639840 is a wasteful number, since it uses less digits than its factorization.

12639840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1584 (or 1576 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 12639840 is about 3555.2552650970. The cubic root of 12639840 is about 232.9416740178.

The spelling of 12639840 in words is "twelve million, six hundred thirty-nine thousand, eight hundred forty".