66988990 has 8 divisors (see below), whose sum is σ = 120580200. Its totient is φ = 26795592.

The previous prime is 66988973. The next prime is 66989023. The reversal of 66988990 is 9988966.

It is a sphenic number, since it is the product of 3 distinct primes.

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 3 ways as a sum of consecutive naturals, for example, 3349440 + ... + 3349459.

It is an arithmetic number, because the mean of its divisors is an integer number (15072525).

Almost surely, 2^66988990 is an apocalyptic number.

66988990 is a deficient number, since it is larger than the sum of its proper divisors (53591210).

66988990 is a wasteful number, since it uses less digits than its factorization.

66988990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6698906.

The product of its (nonzero) digits is 1679616, while the sum is 55.

The square root of 66988990 is about 8184.6802014495. The cubic root of 66988990 is about 406.1325612414.

The spelling of 66988990 in words is "sixty-six million, nine hundred eighty-eight thousand, nine hundred ninety".