12171540 has 24 divisors (see below), whose sum is σ = 34080480. Its totient is φ = 3245728.

The previous prime is 12171539. The next prime is 12171581. The reversal of 12171540 is 4517121.

It is a happy number.

12171540 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, 101370 + ... + 101489.

It is an arithmetic number, because the mean of its divisors is an integer number (1420020).

Almost surely, 2^12171540 is an apocalyptic number.

12171540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12171540 is an abundant number, since it is smaller than the sum of its proper divisors (21908940).

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

12171540 is a wasteful number, since it uses less digits than its factorization.

12171540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202871 (or 202869 counting only the distinct ones).

The product of its (nonzero) digits is 280, while the sum is 21.

The square root of 12171540 is about 3488.7734234255. The cubic root of 12171540 is about 230.0286038780.

Adding to 12171540 its reverse (4517121), we get a palindrome (16688661).

The spelling of 12171540 in words is "twelve million, one hundred seventy-one thousand, five hundred forty".