66764400 has 240 divisors, whose sum is σ = 232485120. Its totient is φ = 16332800.

The previous prime is 66764387. The next prime is 66764449. The reversal of 66764400 is 446766.

It is a tau number, because it is divible by the number of its divisors (240).

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 47 ways as a sum of consecutive naturals, for example, 1131571 + ... + 1131629.

It is an arithmetic number, because the mean of its divisors is an integer number (968688).

Almost surely, 2^66764400 is an apocalyptic number.

66764400 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 66764400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116242560).

66764400 is an abundant number, since it is smaller than the sum of its proper divisors (165720720).

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

66764400 is a wasteful number, since it uses less digits than its factorization.

66764400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144 (or 133 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 33.

The square root of 66764400 is about 8170.9485373486. The cubic root of 66764400 is about 405.6781809153.

It can be divided in two parts, 66 and 764400, that added together give a triangular number (764466 = T₁₂₃₆).

The spelling of 66764400 in words is "sixty-six million, seven hundred sixty-four thousand, four hundred".