66649500 has 96 divisors (see below), whose sum is σ = 215691840. Its totient is φ = 17769600.

The previous prime is 66649489. The next prime is 66649529. The reversal of 66649500 is 594666.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11032 + ... + 15968.

It is an arithmetic number, because the mean of its divisors is an integer number (2246790).

Almost surely, 2^66649500 is an apocalyptic number.

66649500 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66649500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107845920).

66649500 is an abundant number, since it is smaller than the sum of its proper divisors (149042340).

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

66649500 is a wasteful number, since it uses less digits than its factorization.

66649500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4965 (or 4947 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 66649500 is about 8163.9145022471. The cubic root of 66649500 is about 405.4453263391.

The spelling of 66649500 in words is "sixty-six million, six hundred forty-nine thousand, five hundred".