66988240 has 40 divisors (see below), whose sum is σ = 169908768. Its totient is φ = 24359040.

The previous prime is 66988223. The next prime is 66988247. The reversal of 66988240 is 4288966.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66988247) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37182 + ... + 38941.

Almost surely, 2^66988240 is an apocalyptic number.

It is an amenable number.

66988240 is an abundant number, since it is smaller than the sum of its proper divisors (102920528).

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

66988240 is a wasteful number, since it uses less digits than its factorization.

66988240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76147 (or 76141 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 43.

The square root of 66988240 is about 8184.6343840150. The cubic root of 66988240 is about 406.1310455667.

The spelling of 66988240 in words is "sixty-six million, nine hundred eighty-eight thousand, two hundred forty".