66800999 has 2 divisors, whose sum is σ = 66801000. Its totient is φ = 66800998.

The previous prime is 66800971. The next prime is 66801019. The reversal of 66800999 is 99900866.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66800999 - 2²⁴ = 50023783 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66800969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33400499 + 33400500.

It is an arithmetic number, because the mean of its divisors is an integer number (33400500).

Almost surely, 2^66800999 is an apocalyptic number.

66800999 is a deficient number, since it is larger than the sum of its proper divisors (1).

66800999 is an equidigital number, since it uses as much as digits as its factorization.

66800999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 209952, while the sum is 47.

The square root of 66800999 is about 8173.1878113745. The cubic root of 66800999 is about 405.7522957807.

The spelling of 66800999 in words is "sixty-six million, eight hundred thousand, nine hundred ninety-nine".