66780000 has 360 divisors, whose sum is σ = 276324048. Its totient is φ = 14976000.

The previous prime is 66779987. The next prime is 66780031. The reversal of 66780000 is 8766.

It is a tau number, because it is divible by the number of its divisors (360).

It is a Saint-Exupery number, since it is equal to the product of the sides of a Pythagorean triangle: 530 × 450 × 280.

It is a congruent number.

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 59 ways as a sum of consecutive naturals, for example, 1259974 + ... + 1260026.

Almost surely, 2^66780000 is an apocalyptic number.

66780000 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 66780000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138162024).

66780000 is an abundant number, since it is smaller than the sum of its proper divisors (209544048).

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

66780000 is a wasteful number, since it uses less digits than its factorization.

66780000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96 (or 70 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 66780000 is about 8171.9030831257. The cubic root of 66780000 is about 405.7097750323.

Adding to 66780000 its reverse (8766), we get a palindrome (66788766).

The spelling of 66780000 in words is "sixty-six million, seven hundred eighty thousand".