12544821639 has 24 divisors (see below), whose sum is σ = 20846072832. Its totient is φ = 7120990800.

The previous prime is 12544821613. The next prime is 12544821643. The reversal of 12544821639 is 93612844521.

12544821639 is a `hidden beast` number, since 1 + 2 + 5 + 4 + 4 + 8 + 2 + 1 + 639 = 666.

It is not a de Polignac number, because 12544821639 - 2²³ = 12536433031 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12544821594 and 12544821603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12544821689) 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, 649839 + ... + 668864.

It is an arithmetic number, because the mean of its divisors is an integer number (868586368).

Almost surely, 2^12544821639 is an apocalyptic number.

12544821639 is a deficient number, since it is larger than the sum of its proper divisors (8301251193).

12544821639 is a wasteful number, since it uses less digits than its factorization.

12544821639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1318867 (or 1318864 counting only the distinct ones).

The product of its digits is 414720, while the sum is 45.

The spelling of 12544821639 in words is "twelve billion, five hundred forty-four million, eight hundred twenty-one thousand, six hundred thirty-nine".