66707640 has 48 divisors (see below), whose sum is σ = 216801000. Its totient is φ = 17788608.

The previous prime is 66707623. The next prime is 66707647. The reversal of 66707640 is 4670766.

66707640 is a `hidden beast` number, since 6 + 6 + 7 + 0 + 7 + 640 = 666.

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 = 66707595 and 66707604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66707647) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 92290 + ... + 93009.

Almost surely, 2^66707640 is an apocalyptic number.

66707640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66707640 is an abundant number, since it is smaller than the sum of its proper divisors (150093360).

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

66707640 is a wasteful number, since it uses less digits than its factorization.

66707640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185316 (or 185309 counting only the distinct ones).

The product of its (nonzero) digits is 42336, while the sum is 36.

The square root of 66707640 is about 8167.4745178666. The cubic root of 66707640 is about 405.5631853891.

The spelling of 66707640 in words is "sixty-six million, seven hundred seven thousand, six hundred forty".