66801790 has 64 divisors (see below), whose sum is σ = 139138560. Its totient is φ = 22861440.

The previous prime is 66801769. The next prime is 66801793. The reversal of 66801790 is 9710866.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66801793) 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 31 ways as a sum of consecutive naturals, for example, 136927 + ... + 137413.

It is an arithmetic number, because the mean of its divisors is an integer number (2174040).

Almost surely, 2^66801790 is an apocalyptic number.

66801790 is an abundant number, since it is smaller than the sum of its proper divisors (72336770).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66801790 is a wasteful number, since it uses less digits than its factorization.

66801790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 577.

The product of its (nonzero) digits is 18144, while the sum is 37.

The square root of 66801790 is about 8173.2362011629. The cubic root of 66801790 is about 405.7538972976.

The spelling of 66801790 in words is "sixty-six million, eight hundred one thousand, seven hundred ninety".