11781513 has 6 divisors (see below), whose sum is σ = 17017754. Its totient is φ = 7854336.

The previous prime is 11781461. The next prime is 11781521. The reversal of 11781513 is 31518711.

11781513 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 8277129 + 3504384 = 2877^2 + 1872^2 .

It is not a de Polignac number, because 11781513 - 2⁸ = 11781257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11781563) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 654520 + ... + 654537.

Almost surely, 2^11781513 is an apocalyptic number.

It is an amenable number.

11781513 is a deficient number, since it is larger than the sum of its proper divisors (5236241).

11781513 is a wasteful number, since it uses less digits than its factorization.

11781513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1309063 (or 1309060 counting only the distinct ones).

The product of its digits is 840, while the sum is 27.

The square root of 11781513 is about 3432.4208658030. The cubic root of 11781513 is about 227.5448561071.

The spelling of 11781513 in words is "eleven million, seven hundred eighty-one thousand, five hundred thirteen".