66801879 has 6 divisors (see below), whose sum is σ = 96491616. Its totient is φ = 44534580.

The previous prime is 66801859. The next prime is 66801883. The reversal of 66801879 is 97810866.

It is a happy number.

It is not a de Polignac number, because 66801879 - 2¹⁵ = 66769111 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66801809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3711207 + ... + 3711224.

It is an arithmetic number, because the mean of its divisors is an integer number (16081936).

Almost surely, 2^66801879 is an apocalyptic number.

66801879 is a deficient number, since it is larger than the sum of its proper divisors (29689737).

66801879 is a wasteful number, since it uses less digits than its factorization.

66801879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7422437 (or 7422434 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 66801879 is about 8173.2416457609. The cubic root of 66801879 is about 405.7540774928.

The spelling of 66801879 in words is "sixty-six million, eight hundred one thousand, eight hundred seventy-nine".