12721836 has 48 divisors (see below), whose sum is σ = 31046400. Its totient is φ = 4049472.

The previous prime is 12721801. The next prime is 12721843. The reversal of 12721836 is 63812721.

It is a super-2 number, since 2×12721836² = 323690222421792, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48241 + ... + 48503.

It is an arithmetic number, because the mean of its divisors is an integer number (646800).

Almost surely, 2^12721836 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12721836, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15523200).

12721836 is an abundant number, since it is smaller than the sum of its proper divisors (18324564).

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

12721836 is a wasteful number, since it uses less digits than its factorization.

12721836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 438 (or 436 counting only the distinct ones).

The product of its digits is 4032, while the sum is 30.

The square root of 12721836 is about 3566.7682851567. The cubic root of 12721836 is about 233.4442946165. Note that the first 3 decimals are identical.

The spelling of 12721836 in words is "twelve million, seven hundred twenty-one thousand, eight hundred thirty-six".