66815236 has 12 divisors (see below), whose sum is σ = 123804828. Its totient is φ = 31442432.

The previous prime is 66815227. The next prime is 66815239. The reversal of 66815236 is 63251866.

66815236 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 30140100 + 36675136 = 5490^2 + 6056^2 .

It is a junction number, because it is equal to n+sod(n) for n = 66815195 and 66815204.

It is not an unprimeable number, because it can be changed into a prime (66815239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 491221 + ... + 491356.

It is an arithmetic number, because the mean of its divisors is an integer number (10317069).

Almost surely, 2^66815236 is an apocalyptic number.

It is an amenable number.

66815236 is a deficient number, since it is larger than the sum of its proper divisors (56989592).

66815236 is a wasteful number, since it uses less digits than its factorization.

66815236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 982598 (or 982596 counting only the distinct ones).

The product of its digits is 51840, while the sum is 37.

The square root of 66815236 is about 8174.0587225686. The cubic root of 66815236 is about 405.7811191275.

The spelling of 66815236 in words is "sixty-six million, eight hundred fifteen thousand, two hundred thirty-six".