66531187 has 2 divisors, whose sum is σ = 66531188. Its totient is φ = 66531186.

The previous prime is 66531181. The next prime is 66531197. The reversal of 66531187 is 78113566.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66531187 is a prime.

It is not a weakly prime, because it can be changed into another prime (66531181) 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 as a sum of consecutive naturals, namely, 33265593 + 33265594.

It is an arithmetic number, because the mean of its divisors is an integer number (33265594).

Almost surely, 2^66531187 is an apocalyptic number.

66531187 is a deficient number, since it is larger than the sum of its proper divisors (1).

66531187 is an equidigital number, since it uses as much as digits as its factorization.

66531187 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 37.

The square root of 66531187 is about 8156.6651886663. The cubic root of 66531187 is about 405.2052751995.

The spelling of 66531187 in words is "sixty-six million, five hundred thirty-one thousand, one hundred eighty-seven".