8688991 has 2 divisors, whose sum is σ = 8688992. Its totient is φ = 8688990.

The previous prime is 8688961. The next prime is 8688997. The reversal of 8688991 is 1998868.

It is a happy number.

8688991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 8688991 - 2⁷ = 8688863 is a prime.

8688991 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8688997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4344495 + 4344496.

It is an arithmetic number, because the mean of its divisors is an integer number (4344496).

Almost surely, 2^8688991 is an apocalyptic number.

8688991 is a deficient number, since it is larger than the sum of its proper divisors (1).

8688991 is an equidigital number, since it uses as much as digits as its factorization.

8688991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 248832, while the sum is 49.

The square root of 8688991 is about 2947.7094497253. The cubic root of 8688991 is about 205.5842228124.

The spelling of 8688991 in words is "eight million, six hundred eighty-eight thousand, nine hundred ninety-one".