66899933 has 2 divisors, whose sum is σ = 66899934. Its totient is φ = 66899932.

The previous prime is 66899887. The next prime is 66899951. The reversal of 66899933 is 33999866.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51868804 + 15031129 = 7202^2 + 3877^2 .

It is a cyclic number.

It is not a de Polignac number, because 66899933 - 2²⁴ = 50122717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66899983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33449966 + 33449967.

It is an arithmetic number, because the mean of its divisors is an integer number (33449967).

Almost surely, 2^66899933 is an apocalyptic number.

It is an amenable number.

66899933 is a deficient number, since it is larger than the sum of its proper divisors (1).

66899933 is an equidigital number, since it uses as much as digits as its factorization.

66899933 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1889568, while the sum is 53.

The square root of 66899933 is about 8179.2379229363. The cubic root of 66899933 is about 405.9525068407.

The spelling of 66899933 in words is "sixty-six million, eight hundred ninety-nine thousand, nine hundred thirty-three".