12840420 has 24 divisors (see below), whose sum is σ = 35953344. Its totient is φ = 3424096.

The previous prime is 12840391. The next prime is 12840427. The reversal of 12840420 is 2404821.

It is not an unprimeable number, because it can be changed into a prime (12840427) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 106944 + ... + 107063.

It is an arithmetic number, because the mean of its divisors is an integer number (1498056).

Almost surely, 2^12840420 is an apocalyptic number.

12840420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12840420 is an abundant number, since it is smaller than the sum of its proper divisors (23112924).

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

12840420 is a wasteful number, since it uses less digits than its factorization.

12840420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214019 (or 214017 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 21.

The square root of 12840420 is about 3583.3531782396. The cubic root of 12840420 is about 234.1673869919.

The spelling of 12840420 in words is "twelve million, eight hundred forty thousand, four hundred twenty".