66655679 has 8 divisors (see below), whose sum is σ = 69649632. Its totient is φ = 63669760.

The previous prime is 66655669. The next prime is 66655681. The reversal of 66655679 is 97655666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66655679 - 2¹² = 66651583 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66655669) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20399 + ... + 23439.

It is an arithmetic number, because the mean of its divisors is an integer number (8706204).

Almost surely, 2^66655679 is an apocalyptic number.

66655679 is a deficient number, since it is larger than the sum of its proper divisors (2993953).

66655679 is a wasteful number, since it uses less digits than its factorization.

66655679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4017.

The product of its digits is 2041200, while the sum is 50.

The square root of 66655679 is about 8164.2929271309. The cubic root of 66655679 is about 405.4578554116.

The spelling of 66655679 in words is "sixty-six million, six hundred fifty-five thousand, six hundred seventy-nine".