66091331 has 2 divisors, whose sum is σ = 66091332. Its totient is φ = 66091330.

The previous prime is 66091313. The next prime is 66091339. The reversal of 66091331 is 13319066.

Together with previous prime (66091313) 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 66091331 - 2¹⁴ = 66074947 is a prime.

It is a super-2 number, since 2×66091331² = 8736128066703122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66091294 and 66091303.

It is not a weakly prime, because it can be changed into another prime (66091339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33045665 + 33045666.

It is an arithmetic number, because the mean of its divisors is an integer number (33045666).

Almost surely, 2^66091331 is an apocalyptic number.

66091331 is a deficient number, since it is larger than the sum of its proper divisors (1).

66091331 is an equidigital number, since it uses as much as digits as its factorization.

66091331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2916, while the sum is 29.

The square root of 66091331 is about 8129.6574958604. The cubic root of 66091331 is about 404.3103254832.

The spelling of 66091331 in words is "sixty-six million, ninety-one thousand, three hundred thirty-one".