66989928 has 32 divisors (see below), whose sum is σ = 177327360. Its totient is φ = 21016320.

The previous prime is 66989917. The next prime is 66989939. The reversal of 66989928 is 82998966.

It is an interprime number because it is at equal distance from previous prime (66989917) and next prime (66989939).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81688 + ... + 82503.

It is an arithmetic number, because the mean of its divisors is an integer number (5541480).

Almost surely, 2^66989928 is an apocalyptic number.

66989928 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

66989928 is an abundant number, since it is smaller than the sum of its proper divisors (110337432).

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

66989928 is a wasteful number, since it uses less digits than its factorization.

66989928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164217 (or 164213 counting only the distinct ones).

The product of its digits is 3359232, while the sum is 57.

The square root of 66989928 is about 8184.7375034267. The cubic root of 66989928 is about 406.1344568294.

The spelling of 66989928 in words is "sixty-six million, nine hundred eighty-nine thousand, nine hundred twenty-eight".