66966919 has 2 divisors, whose sum is σ = 66966920. Its totient is φ = 66966918.

The previous prime is 66966917. The next prime is 66966967. The reversal of 66966919 is 91966966.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66966919 - 2¹ = 66966917 is a prime.

It is a super-2 number, since 2×66966919² = 8969136480705122, which contains 22 as substring.

Together with 66966917, 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 (66966917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33483459 + 33483460.

It is an arithmetic number, because the mean of its divisors is an integer number (33483460).

Almost surely, 2^66966919 is an apocalyptic number.

66966919 is a deficient number, since it is larger than the sum of its proper divisors (1).

66966919 is an equidigital number, since it uses as much as digits as its factorization.

66966919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 944784, while the sum is 52.

The square root of 66966919 is about 8183.3317786828. The cubic root of 66966919 is about 406.0879532326.

The spelling of 66966919 in words is "sixty-six million, nine hundred sixty-six thousand, nine hundred nineteen".