66784258831 has 2 divisors, whose sum is σ = 66784258832. Its totient is φ = 66784258830.

The previous prime is 66784258817. The next prime is 66784258837. The reversal of 66784258831 is 13885248766.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66784258831 - 2¹⁷ = 66784127759 is a prime.

It is a super-2 number, since 2×66784258831² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66784258837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33392129415 + 33392129416.

It is an arithmetic number, because the mean of its divisors is an integer number (33392129416).

Almost surely, 2^66784258831 is an apocalyptic number.

66784258831 is a deficient number, since it is larger than the sum of its proper divisors (1).

66784258831 is an equidigital number, since it uses as much as digits as its factorization.

66784258831 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15482880, while the sum is 58.

The spelling of 66784258831 in words is "sixty-six billion, seven hundred eighty-four million, two hundred fifty-eight thousand, eight hundred thirty-one".