66398251831 has 2 divisors, whose sum is σ = 66398251832. Its totient is φ = 66398251830.

The previous prime is 66398251807. The next prime is 66398251853. The reversal of 66398251831 is 13815289366.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66398251831 - 2⁹ = 66398251319 is a prime.

It is a super-2 number, since 2×66398251831² (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 (66398252831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33199125915 + 33199125916.

It is an arithmetic number, because the mean of its divisors is an integer number (33199125916).

Almost surely, 2^66398251831 is an apocalyptic number.

66398251831 is a deficient number, since it is larger than the sum of its proper divisors (1).

66398251831 is an equidigital number, since it uses as much as digits as its factorization.

66398251831 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1866240, while the sum is 52.

The spelling of 66398251831 in words is "sixty-six billion, three hundred ninety-eight million, two hundred fifty-one thousand, eight hundred thirty-one".