12538681 has 3 divisors (see below), whose sum is σ = 12542223. Its totient is φ = 12535140.

The previous prime is 12538679. The next prime is 12538723. The reversal of 12538681 is 18683521.

The square root of 12538681 is 3541.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 5248681 + 7290000 = 2291^2 + 2700^2 .

It is not a de Polignac number, because 12538681 - 2¹ = 12538679 is a prime.

It is a super-2 number, since 2×12538681² = 314437042439522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12538181) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 1771 + ... + 5311.

It is an arithmetic number, because the mean of its divisors is an integer number (4180741).

Almost surely, 2^12538681 is an apocalyptic number.

12538681 is the 3541-st square number.

12538681 is the 1771-st centered octagonal number.

It is an amenable number.

12538681 is a deficient number, since it is larger than the sum of its proper divisors (3542).

12538681 is an frugal number, since it uses more digits than its factorization.

12538681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7082 (or 3541 counting only the distinct ones).

The product of its digits is 11520, while the sum is 34.

The cubic root of 12538681 is about 232.3185835736.

The spelling of 12538681 in words is "twelve million, five hundred thirty-eight thousand, six hundred eighty-one".