66749760 has 504 divisors, whose sum is σ = 298130976. Its totient is φ = 13547520.

The previous prime is 66749759. The next prime is 66749783. The reversal of 66749760 is 6794766.

It is a tau number, because it is divible by the number of its divisors (504).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1552299 + ... + 1552341.

Almost surely, 2^66749760 is an apocalyptic number.

66749760 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 66749760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149065488).

66749760 is an abundant number, since it is smaller than the sum of its proper divisors (231381216).

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

66749760 is a wasteful number, since it uses less digits than its factorization.

66749760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 381024, while the sum is 45.

The square root of 66749760 is about 8170.0526314094. The cubic root of 66749760 is about 405.6485265750.

The spelling of 66749760 in words is "sixty-six million, seven hundred forty-nine thousand, seven hundred sixty".