66809436 has 24 divisors (see below), whose sum is σ = 156451344. Its totient is φ = 22189440.

The previous prime is 66809399. The next prime is 66809443. The reversal of 66809436 is 63490866.

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, 6535 + ... + 13278.

It is an arithmetic number, because the mean of its divisors is an integer number (6518806).

Almost surely, 2^66809436 is an apocalyptic number.

It is an amenable number.

66809436 is an abundant number, since it is smaller than the sum of its proper divisors (89641908).

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

66809436 is a wasteful number, since it uses less digits than its factorization.

66809436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20101 (or 20099 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 42.

The square root of 66809436 is about 8173.7039339580. The cubic root of 66809436 is about 405.7693773017.

The spelling of 66809436 in words is "sixty-six million, eight hundred nine thousand, four hundred thirty-six".