66740831 has 2 divisors, whose sum is σ = 66740832. Its totient is φ = 66740830.

The previous prime is 66740813. The next prime is 66740837. The reversal of 66740831 is 13804766.

Together with previous prime (66740813) 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 66740831 - 2⁶ = 66740767 is a prime.

It is a super-2 number, since 2×66740831² = 8908677045141122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66740791 and 66740800.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66740837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33370415 + 33370416.

It is an arithmetic number, because the mean of its divisors is an integer number (33370416).

Almost surely, 2^66740831 is an apocalyptic number.

66740831 is a deficient number, since it is larger than the sum of its proper divisors (1).

66740831 is an equidigital number, since it uses as much as digits as its factorization.

66740831 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 35.

The square root of 66740831 is about 8169.5061662257. The cubic root of 66740831 is about 405.6304381343.

The spelling of 66740831 in words is "sixty-six million, seven hundred forty thousand, eight hundred thirty-one".