66768769 has 4 divisors (see below), whose sum is σ = 67573296. Its totient is φ = 65964244.

The previous prime is 66768763. The next prime is 66768781. The reversal of 66768769 is 96786766.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66768769 - 2⁹ = 66768257 is a prime.

It is a super-2 number, since 2×66768769² = 8916137027550722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66768763) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 402139 + ... + 402304.

It is an arithmetic number, because the mean of its divisors is an integer number (16893324).

Almost surely, 2^66768769 is an apocalyptic number.

It is an amenable number.

66768769 is a deficient number, since it is larger than the sum of its proper divisors (804527).

66768769 is an equidigital number, since it uses as much as digits as its factorization.

66768769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 804526.

The product of its digits is 4572288, while the sum is 55.

The square root of 66768769 is about 8171.2158825967. The cubic root of 66768769 is about 405.6870297895.

The spelling of 66768769 in words is "sixty-six million, seven hundred sixty-eight thousand, seven hundred sixty-nine".