13268781 has 12 divisors (see below), whose sum is σ = 19481020. Its totient is φ = 8700480.

The previous prime is 13268777. The next prime is 13268791. The reversal of 13268781 is 18786231.

It can be written as a sum of positive squares in 2 ways, for example, as 6812100 + 6456681 = 2610^2 + 2541^2 .

It is not a de Polignac number, because 13268781 - 2² = 13268777 is a prime.

It is a super-2 number, since 2×13268781² = 352121098451922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13268791) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11536 + ... + 12633.

Almost surely, 2^13268781 is an apocalyptic number.

It is an amenable number.

13268781 is a deficient number, since it is larger than the sum of its proper divisors (6212239).

13268781 is a wasteful number, since it uses less digits than its factorization.

13268781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24236 (or 24233 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 13268781 is about 3642.6337998761. The cubic root of 13268781 is about 236.7429247964.

The spelling of 13268781 in words is "thirteen million, two hundred sixty-eight thousand, seven hundred eighty-one".