11817997 has 2 divisors, whose sum is σ = 11817998. Its totient is φ = 11817996.

The previous prime is 11817983. The next prime is 11818007. The reversal of 11817997 is 79971811.

11817997 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9449476 + 2368521 = 3074^2 + 1539^2 .

It is an emirp because it is prime and its reverse (79971811) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11817997 - 2¹¹ = 11815949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11817937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5908998 + 5908999.

It is an arithmetic number, because the mean of its divisors is an integer number (5908999).

Almost surely, 2^11817997 is an apocalyptic number.

It is an amenable number.

11817997 is a deficient number, since it is larger than the sum of its proper divisors (1).

11817997 is an equidigital number, since it uses as much as digits as its factorization.

11817997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31752, while the sum is 43.

The square root of 11817997 is about 3437.7313740314. The cubic root of 11817997 is about 227.7794946706.

The spelling of 11817997 in words is "eleven million, eight hundred seventeen thousand, nine hundred ninety-seven".