66893531 has 2 divisors, whose sum is σ = 66893532. Its totient is φ = 66893530.

The previous prime is 66893513. The next prime is 66893543. The reversal of 66893531 is 13539866.

Together with previous prime (66893513) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66893531 - 2¹⁸ = 66631387 is a prime.

It is a super-2 number, since 2×66893531² = 8949488979295922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66893501) 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, 33446765 + 33446766.

It is an arithmetic number, because the mean of its divisors is an integer number (33446766).

Almost surely, 2^66893531 is an apocalyptic number.

66893531 is a deficient number, since it is larger than the sum of its proper divisors (1).

66893531 is an equidigital number, since it uses as much as digits as its factorization.

66893531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 116640, while the sum is 41.

The square root of 66893531 is about 8178.8465568196. The cubic root of 66893531 is about 405.9395571972.

The spelling of 66893531 in words is "sixty-six million, eight hundred ninety-three thousand, five hundred thirty-one".