66956779 has 4 divisors (see below), whose sum is σ = 70480840. Its totient is φ = 63432720.

The previous prime is 66956777. The next prime is 66956797. The reversal of 66956779 is 97765966.

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

It is a cyclic number.

It is not a de Polignac number, because 66956779 - 2¹ = 66956777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66956777) 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, 1762002 + ... + 1762039.

It is an arithmetic number, because the mean of its divisors is an integer number (17620210).

Almost surely, 2^66956779 is an apocalyptic number.

66956779 is a deficient number, since it is larger than the sum of its proper divisors (3524061).

66956779 is a wasteful number, since it uses less digits than its factorization.

66956779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3524060.

The product of its digits is 4286520, while the sum is 55.

The square root of 66956779 is about 8182.7122031757. The cubic root of 66956779 is about 406.0674558499.

The spelling of 66956779 in words is "sixty-six million, nine hundred fifty-six thousand, seven hundred seventy-nine".