12721731 has 16 divisors (see below), whose sum is σ = 18593280. Its totient is φ = 7673120.

The previous prime is 12721721. The next prime is 12721739. The reversal of 12721731 is 13712721.

It is a cyclic number.

It is not a de Polignac number, because 12721731 - 2¹⁰ = 12720707 is a prime.

It is a super-2 number, since 2×12721731² = 323684879272722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (12721739) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7081 + ... + 8693.

It is an arithmetic number, because the mean of its divisors is an integer number (1162080).

Almost surely, 2^12721731 is an apocalyptic number.

12721731 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

12721731 is a deficient number, since it is larger than the sum of its proper divisors (5871549).

12721731 is a wasteful number, since it uses less digits than its factorization.

12721731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1866.

The product of its digits is 588, while the sum is 24.

The square root of 12721731 is about 3566.7535659196. The cubic root of 12721731 is about 233.4436523685.

It can be divided in two parts, 1272 and 1731, that added together give a palindrome (3003).

The spelling of 12721731 in words is "twelve million, seven hundred twenty-one thousand, seven hundred thirty-one".