12840534 has 48 divisors (see below), whose sum is σ = 32142240. Its totient is φ = 3628800.

The previous prime is 12840493. The next prime is 12840539. The reversal of 12840534 is 43504821.

12840534 is a `hidden beast` number, since 128 + 4 + 0 + 534 = 666.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 12840498 and 12840507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12840539) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12222 + ... + 13230.

It is an arithmetic number, because the mean of its divisors is an integer number (669630).

Almost surely, 2^12840534 is an apocalyptic number.

12840534 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 12840534, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16071120).

12840534 is an abundant number, since it is smaller than the sum of its proper divisors (19301706).

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

12840534 is a wasteful number, since it uses less digits than its factorization.

12840534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1125 (or 1122 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 12840534 is about 3583.3690850930. The cubic root of 12840534 is about 234.1680799860.

The spelling of 12840534 in words is "twelve million, eight hundred forty thousand, five hundred thirty-four".