66531131 has 2 divisors, whose sum is σ = 66531132. Its totient is φ = 66531130.

The previous prime is 66531107. The next prime is 66531137. The reversal of 66531131 is 13113566.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66531131 is a prime.

It is a super-2 number, since 2×66531131² = 8852782784278322, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66531131.

It is not a weakly prime, because it can be changed into another prime (66531137) 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, 33265565 + 33265566.

It is an arithmetic number, because the mean of its divisors is an integer number (33265566).

Almost surely, 2^66531131 is an apocalyptic number.

66531131 is a deficient number, since it is larger than the sum of its proper divisors (1).

66531131 is an equidigital number, since it uses as much as digits as its factorization.

66531131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1620, while the sum is 26.

The square root of 66531131 is about 8156.6617558901. The cubic root of 66531131 is about 405.2051615110.

Adding to 66531131 its reverse (13113566), we get a palindrome (79644697).

The spelling of 66531131 in words is "sixty-six million, five hundred thirty-one thousand, one hundred thirty-one".