12639219840 has 384 divisors, whose sum is σ = 49771940400. Its totient is φ = 2927886336.

The previous prime is 12639219833. The next prime is 12639219841. The reversal of 12639219840 is 4891293621.

12639219840 is a `hidden beast` number, since 1 + 2 + 639 + 2 + 1 + 9 + 8 + 4 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 3017964096 + 9621255744 = 54936^2 + 98088^2 .

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (12639219841) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1267996 + ... + 1277924.

Almost surely, 2^12639219840 is an apocalyptic number.

12639219840 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 12639219840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24885970200).

12639219840 is an abundant number, since it is smaller than the sum of its proper divisors (37132720560).

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

12639219840 is a wasteful number, since it uses less digits than its factorization.

12639219840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9984 (or 9969 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The spelling of 12639219840 in words is "twelve billion, six hundred thirty-nine million, two hundred nineteen thousand, eight hundred forty".