66899900 has 18 divisors (see below), whose sum is σ = 145173000. Its totient is φ = 26759920.

The previous prime is 66899887. The next prime is 66899933. The reversal of 66899900 is 999866.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 334400 + ... + 334599.

Almost surely, 2^66899900 is an apocalyptic number.

It is an amenable number.

66899900 is an abundant number, since it is smaller than the sum of its proper divisors (78273100).

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

66899900 is a wasteful number, since it uses less digits than its factorization.

66899900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 669013 (or 669006 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 47.

The square root of 66899900 is about 8179.2359056332. The cubic root of 66899900 is about 405.9524400921.

The spelling of 66899900 in words is "sixty-six million, eight hundred ninety-nine thousand, nine hundred".