12721936 has 10 divisors (see below), whose sum is σ = 24648782. Its totient is φ = 6360960.

The previous prime is 12721903. The next prime is 12721939. The reversal of 12721936 is 63912721.

It can be written as a sum of positive squares in only one way, i.e., 6471936 + 6250000 = 2544^2 + 2500^2 .

It is a junction number, because it is equal to n+sod(n) for n = 12721898 and 12721907.

It is not an unprimeable number, because it can be changed into a prime (12721939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 397545 + ... + 397576.

Almost surely, 2^12721936 is an apocalyptic number.

12721936 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

12721936 is a deficient number, since it is larger than the sum of its proper divisors (11926846).

12721936 is an equidigital number, since it uses as much as digits as its factorization.

12721936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 795129 (or 795123 counting only the distinct ones).

The product of its digits is 4536, while the sum is 31.

The square root of 12721936 is about 3566.7823034214. The cubic root of 12721936 is about 233.4449062779. Note that the first 3 decimals are identical.

It can be divided in two parts, 127 and 21936, that multiplied together give a palindrome (2785872).

The spelling of 12721936 in words is "twelve million, seven hundred twenty-one thousand, nine hundred thirty-six".