13256781 has 8 divisors (see below), whose sum is σ = 17695104. Its totient is φ = 8828160.

The previous prime is 13256777. The next prime is 13256797. The reversal of 13256781 is 18765231.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 13256781 - 2² = 13256777 is a prime.

It is a super-2 number, since 2×13256781² = 351484484963922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13256701) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1836 + ... + 5466.

It is an arithmetic number, because the mean of its divisors is an integer number (2211888).

Almost surely, 2^13256781 is an apocalyptic number.

It is an amenable number.

13256781 is a deficient number, since it is larger than the sum of its proper divisors (4438323).

13256781 is a wasteful number, since it uses less digits than its factorization.

13256781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4851.

The product of its digits is 10080, while the sum is 33.

The square root of 13256781 is about 3640.9862674830. The cubic root of 13256781 is about 236.6715348687.

The spelling of 13256781 in words is "thirteen million, two hundred fifty-six thousand, seven hundred eighty-one".