66989740 has 24 divisors (see below), whose sum is σ = 141548400. Its totient is φ = 26630208.

The previous prime is 66989737. The next prime is 66989753. The reversal of 66989740 is 4798966.

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, 7015 + ... + 13534.

It is an arithmetic number, because the mean of its divisors is an integer number (5897850).

Almost surely, 2^66989740 is an apocalyptic number.

It is an amenable number.

66989740 is an abundant number, since it is smaller than the sum of its proper divisors (74558660).

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

66989740 is a wasteful number, since it uses less digits than its factorization.

66989740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20721 (or 20719 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 49.

The square root of 66989740 is about 8184.7260186276. The cubic root of 66989740 is about 406.1340769049.

It can be divided in two parts, 669 and 89740, that added together give a palindrome (90409).

The spelling of 66989740 in words is "sixty-six million, nine hundred eighty-nine thousand, seven hundred forty".