12639816 has 96 divisors (see below), whose sum is σ = 40435200. Its totient is φ = 3490560.

The previous prime is 12639793. The next prime is 12639817. The reversal of 12639816 is 61893621.

12639816 is a `hidden beast` number, since 1 + 2 + 639 + 8 + 16 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (12639817) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15220 + ... + 16028.

It is an arithmetic number, because the mean of its divisors is an integer number (421200).

Almost surely, 2^12639816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12639816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20217600).

12639816 is an abundant number, since it is smaller than the sum of its proper divisors (27795384).

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

12639816 is a wasteful number, since it uses less digits than its factorization.

12639816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 859 (or 852 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 12639816 is about 3555.2518898103. The cubic root of 12639816 is about 232.9415265844.

The spelling of 12639816 in words is "twelve million, six hundred thirty-nine thousand, eight hundred sixteen".