11781389 has 2 divisors, whose sum is σ = 11781390. Its totient is φ = 11781388.

The previous prime is 11781383. The next prime is 11781421. The reversal of 11781389 is 98318711.

11781389 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10176100 + 1605289 = 3190^2 + 1267^2 .

It is a cyclic number.

It is not a de Polignac number, because 11781389 - 2¹⁶ = 11715853 is a prime.

It is a super-2 number, since 2×11781389² = 277602253538642, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11781383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5890694 + 5890695.

It is an arithmetic number, because the mean of its divisors is an integer number (5890695).

Almost surely, 2^11781389 is an apocalyptic number.

It is an amenable number.

11781389 is a deficient number, since it is larger than the sum of its proper divisors (1).

11781389 is an equidigital number, since it uses as much as digits as its factorization.

11781389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 38.

The square root of 11781389 is about 3432.4028027025. The cubic root of 11781389 is about 227.5440578038.

The spelling of 11781389 in words is "eleven million, seven hundred eighty-one thousand, three hundred eighty-nine".