66969697 has 4 divisors (see below), whose sum is σ = 67119300. Its totient is φ = 66820096.

The previous prime is 66969677. The next prime is 66969713. The reversal of 66969697 is 79696966.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20511841 + 46457856 = 4529^2 + 6816^2 .

It is a cyclic number.

It is not a de Polignac number, because 66969697 - 2⁷ = 66969569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66969607) 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, 74128 + ... + 75025.

It is an arithmetic number, because the mean of its divisors is an integer number (16779825).

Almost surely, 2^66969697 is an apocalyptic number.

It is an amenable number.

66969697 is a deficient number, since it is larger than the sum of its proper divisors (149603).

66969697 is a wasteful number, since it uses less digits than its factorization.

66969697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149602.

The product of its digits is 6613488, while the sum is 58.

The square root of 66969697 is about 8183.5015121890. The cubic root of 66969697 is about 406.0935684267.

The spelling of 66969697 in words is "sixty-six million, nine hundred sixty-nine thousand, six hundred ninety-seven".