66669719 has 2 divisors, whose sum is σ = 66669720. Its totient is φ = 66669718.

The previous prime is 66669683. The next prime is 66669739. The reversal of 66669719 is 91796666.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66669719 - 2²⁴ = 49892503 is a prime.

It is a super-2 number, since 2×66669719² = 8889702863077922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66669739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33334859 + 33334860.

It is an arithmetic number, because the mean of its divisors is an integer number (33334860).

Almost surely, 2^66669719 is an apocalyptic number.

66669719 is a deficient number, since it is larger than the sum of its proper divisors (1).

66669719 is an equidigital number, since it uses as much as digits as its factorization.

66669719 is an evil number, because the sum of its binary digits is even.

The product of its digits is 734832, while the sum is 50.

The square root of 66669719 is about 8165.1527236176. The cubic root of 66669719 is about 405.4863212464.

The spelling of 66669719 in words is "sixty-six million, six hundred sixty-nine thousand, seven hundred nineteen".