12505426638 has 16 divisors (see below), whose sum is σ = 25482756816. Its totient is φ = 4089824960.

The previous prime is 12505426613. The next prime is 12505426657. The reversal of 12505426638 is 83662450521.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 12505426638.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19662303 + ... + 19662938.

It is an arithmetic number, because the mean of its divisors is an integer number (1592672301).

Almost surely, 2^12505426638 is an apocalyptic number.

12505426638 is an abundant number, since it is smaller than the sum of its proper divisors (12977330178).

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

12505426638 is a wasteful number, since it uses less digits than its factorization.

12505426638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39325299.

The product of its (nonzero) digits is 345600, while the sum is 42.

The spelling of 12505426638 in words is "twelve billion, five hundred five million, four hundred twenty-six thousand, six hundred thirty-eight".