66947899 has 2 divisors, whose sum is σ = 66947900. Its totient is φ = 66947898.

The previous prime is 66947893. The next prime is 66947953. The reversal of 66947899 is 99874966.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66947899 - 2³ = 66947891 is a prime.

It is not a weakly prime, because it can be changed into another prime (66947891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33473949 + 33473950.

It is an arithmetic number, because the mean of its divisors is an integer number (33473950).

Almost surely, 2^66947899 is an apocalyptic number.

66947899 is a deficient number, since it is larger than the sum of its proper divisors (1).

66947899 is an equidigital number, since it uses as much as digits as its factorization.

66947899 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5878656, while the sum is 58.

The square root of 66947899 is about 8182.1695778076. The cubic root of 66947899 is about 406.0495037796.

The spelling of 66947899 in words is "sixty-six million, nine hundred forty-seven thousand, eight hundred ninety-nine".