66779291 has 4 divisors (see below), whose sum is σ = 66805800. Its totient is φ = 66752784.

The previous prime is 66779269. The next prime is 66779299. The reversal of 66779291 is 19297766.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19297766 = 2 ⋅9648883.

It is a cyclic number.

It is not a de Polignac number, because 66779291 - 2¹⁰ = 66778267 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66779299) 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, 9026 + ... + 14663.

It is an arithmetic number, because the mean of its divisors is an integer number (16701450).

Almost surely, 2^66779291 is an apocalyptic number.

66779291 is a deficient number, since it is larger than the sum of its proper divisors (26509).

66779291 is a wasteful number, since it uses less digits than its factorization.

66779291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26508.

The product of its digits is 285768, while the sum is 47.

The square root of 66779291 is about 8171.8597026625. The cubic root of 66779291 is about 405.7083392269.

The spelling of 66779291 in words is "sixty-six million, seven hundred seventy-nine thousand, two hundred ninety-one".