66764340 has 72 divisors (see below), whose sum is σ = 205333128. Its totient is φ = 17556480.

The previous prime is 66764339. The next prime is 66764371. The reversal of 66764340 is 4346766.

66764340 is a `hidden beast` number, since 6 + 6 + 7 + 643 + 4 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1542564 + 65221776 = 1242^2 + 8076^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 66764295 and 66764304.

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 23 ways as a sum of consecutive naturals, for example, 10600 + ... + 15680.

It is an arithmetic number, because the mean of its divisors is an integer number (2851849).

Almost surely, 2^66764340 is an apocalyptic number.

66764340 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 66764340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102666564).

66764340 is an abundant number, since it is smaller than the sum of its proper divisors (138568788).

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

66764340 is a wasteful number, since it uses less digits than its factorization.

66764340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5169 (or 5164 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 36.

The square root of 66764340 is about 8170.9448658035. The cubic root of 66764340 is about 405.6780593900.

The spelling of 66764340 in words is "sixty-six million, seven hundred sixty-four thousand, three hundred forty".