66347731 has 2 divisors, whose sum is σ = 66347732. Its totient is φ = 66347730.

The previous prime is 66347713. The next prime is 66347741. The reversal of 66347731 is 13774366.

Together with previous prime (66347713) 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 66347731 - 2²¹ = 64250579 is a prime.

It is a super-2 number, since 2×66347731² = 8804042817696722, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66347741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33173865 + 33173866.

It is an arithmetic number, because the mean of its divisors is an integer number (33173866).

Almost surely, 2^66347731 is an apocalyptic number.

66347731 is a deficient number, since it is larger than the sum of its proper divisors (1).

66347731 is an equidigital number, since it uses as much as digits as its factorization.

66347731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 63504, while the sum is 37.

The square root of 66347731 is about 8145.4116531947. The cubic root of 66347731 is about 404.8324887706.

It can be divided in two parts, 6634 and 7731, that added together give a triangular number (14365 = T₁₆₉).

The spelling of 66347731 in words is "sixty-six million, three hundred forty-seven thousand, seven hundred thirty-one".