12540021278399 has 4 divisors (see below), whose sum is σ = 12540045471480. Its totient is φ = 12539997085320.

The previous prime is 12540021278353. The next prime is 12540021278401. The reversal of 12540021278399 is 99387212004521.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 12540021278399 - 2²⁰ = 12540020229823 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12540021278399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12540021271399) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11301632 + ... + 12361509.

It is an arithmetic number, because the mean of its divisors is an integer number (3135011367870).

Almost surely, 2^{12540021278399} is an apocalyptic number.

12540021278399 is a deficient number, since it is larger than the sum of its proper divisors (24193081).

12540021278399 is an equidigital number, since it uses as much as digits as its factorization.

12540021278399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24193080.

The product of its (nonzero) digits is 2177280, while the sum is 53.

The spelling of 12540021278399 in words is "twelve trillion, five hundred forty billion, twenty-one million, two hundred seventy-eight thousand, three hundred ninety-nine".