12540320205 has 32 divisors (see below), whose sum is σ = 23133821184. Its totient is φ = 5681980416.

The previous prime is 12540320189. The next prime is 12540320213. The reversal of 12540320205 is 50202304521.

It is not a de Polignac number, because 12540320205 - 2⁴ = 12540320189 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 516594 + ... + 540323.

It is an arithmetic number, because the mean of its divisors is an integer number (722931912).

Almost surely, 2^12540320205 is an apocalyptic number.

12540320205 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12540320205 is a deficient number, since it is larger than the sum of its proper divisors (10593500979).

12540320205 is a wasteful number, since it uses less digits than its factorization.

12540320205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1057045.

The product of its (nonzero) digits is 2400, while the sum is 24.

Adding to 12540320205 its reverse (50202304521), we get a palindrome (62742624726).

The spelling of 12540320205 in words is "twelve billion, five hundred forty million, three hundred twenty thousand, two hundred five".