66604537 has 4 divisors (see below), whose sum is σ = 66627216. Its totient is φ = 66581860.

The previous prime is 66604529. The next prime is 66604547. The reversal of 66604537 is 73540666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 73540666 = 2 ⋅36770333.

It is a cyclic number.

It is not a de Polignac number, because 66604537 - 2³ = 66604529 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66604496 and 66604505.

It is not an unprimeable number, because it can be changed into a prime (66604507) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 6139 + ... + 13072.

It is an arithmetic number, because the mean of its divisors is an integer number (16656804).

Almost surely, 2^66604537 is an apocalyptic number.

It is an amenable number.

66604537 is a deficient number, since it is larger than the sum of its proper divisors (22679).

66604537 is a wasteful number, since it uses less digits than its factorization.

66604537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22678.

The product of its (nonzero) digits is 90720, while the sum is 37.

The square root of 66604537 is about 8161.1602729024. The cubic root of 66604537 is about 405.3541321606.

The spelling of 66604537 in words is "sixty-six million, six hundred four thousand, five hundred thirty-seven".