12540139 has 4 divisors (see below), whose sum is σ = 12547224. Its totient is φ = 12533056.

The previous prime is 12540127. The next prime is 12540149. The reversal of 12540139 is 93104521.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 93104521 = 9181 ⋅10141.

It is a cyclic number.

It is not a de Polignac number, because 12540139 - 2¹⁵ = 12507371 is a prime.

It is a super-2 number, since 2×12540139² = 314510172278642, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12540109) 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, 1659 + ... + 5275.

It is an arithmetic number, because the mean of its divisors is an integer number (3136806).

Almost surely, 2^12540139 is an apocalyptic number.

12540139 is a deficient number, since it is larger than the sum of its proper divisors (7085).

12540139 is an equidigital number, since it uses as much as digits as its factorization.

12540139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7084.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 12540139 is about 3541.2058680625. The cubic root of 12540139 is about 232.3275879064.

The spelling of 12540139 in words is "twelve million, five hundred forty thousand, one hundred thirty-nine".