66915769 has 2 divisors, whose sum is σ = 66915770. Its totient is φ = 66915768.

The previous prime is 66915713. The next prime is 66915773. The reversal of 66915769 is 96751966.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36445369 + 30470400 = 6037^2 + 5520^2 .

It is a cyclic number.

It is not a de Polignac number, because 66915769 - 2¹⁵ = 66883001 is a prime.

It is a super-2 number, since 2×66915769² = 8955440281722722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66915799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33457884 + 33457885.

It is an arithmetic number, because the mean of its divisors is an integer number (33457885).

Almost surely, 2^66915769 is an apocalyptic number.

It is an amenable number.

66915769 is a deficient number, since it is larger than the sum of its proper divisors (1).

66915769 is an equidigital number, since it uses as much as digits as its factorization.

66915769 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 612360, while the sum is 49.

The square root of 66915769 is about 8180.2059265033. The cubic root of 66915769 is about 405.9845355560.

The spelling of 66915769 in words is "sixty-six million, nine hundred fifteen thousand, seven hundred sixty-nine".