66756537 has 6 divisors (see below), whose sum is σ = 96426122. Its totient is φ = 44504352.

The previous prime is 66756533. The next prime is 66756539. The reversal of 66756537 is 73565766.

66756537 is a `hidden beast` number, since 6 + 67 + 56 + 537 = 666.

It can be written as a sum of positive squares in only one way, i.e., 61168041 + 5588496 = 7821^2 + 2364^2 .

It is not a de Polignac number, because 66756537 - 2² = 66756533 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66756492 and 66756501.

It is not an unprimeable number, because it can be changed into a prime (66756533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3708688 + ... + 3708705.

Almost surely, 2^66756537 is an apocalyptic number.

It is an amenable number.

66756537 is a deficient number, since it is larger than the sum of its proper divisors (29669585).

66756537 is a wasteful number, since it uses less digits than its factorization.

66756537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7417399 (or 7417396 counting only the distinct ones).

The product of its digits is 793800, while the sum is 45.

The square root of 66756537 is about 8170.4673672930. The cubic root of 66756537 is about 405.6622543998.

The spelling of 66756537 in words is "sixty-six million, seven hundred fifty-six thousand, five hundred thirty-seven".