66405812 has 24 divisors (see below), whose sum is σ = 128089920. Its totient is φ = 29871360.

The previous prime is 66405799. The next prime is 66405821. The reversal of 66405812 is 21850466.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3512 + ... + 12047.

It is an arithmetic number, because the mean of its divisors is an integer number (5337080).

Almost surely, 2^66405812 is an apocalyptic number.

It is an amenable number.

66405812 is a deficient number, since it is larger than the sum of its proper divisors (61684108).

66405812 is a wasteful number, since it uses less digits than its factorization.

66405812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15671 (or 15669 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 66405812 is about 8148.9761320058. The cubic root of 66405812 is about 404.9505848362.

The spelling of 66405812 in words is "sixty-six million, four hundred five thousand, eight hundred twelve".