866161663 has 2 divisors, whose sum is σ = 866161664. Its totient is φ = 866161662.

The previous prime is 866161661. The next prime is 866161691. The reversal of 866161663 is 366161668.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 866161663 - 2¹ = 866161661 is a prime.

Together with 866161661, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866161661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433080831 + 433080832.

It is an arithmetic number, because the mean of its divisors is an integer number (433080832).

Almost surely, 2^866161663 is an apocalyptic number.

866161663 is a deficient number, since it is larger than the sum of its proper divisors (1).

866161663 is an equidigital number, since it uses as much as digits as its factorization.

866161663 is an evil number, because the sum of its binary digits is even.

The product of its digits is 186624, while the sum is 43.

The square root of 866161663 is about 29430.6245771305. The cubic root of 866161663 is about 953.2342812661.

The spelling of 866161663 in words is "eight hundred sixty-six million, one hundred sixty-one thousand, six hundred sixty-three".