66500831 has 2 divisors, whose sum is σ = 66500832. Its totient is φ = 66500830.

The previous prime is 66500809. The next prime is 66500851. The reversal of 66500831 is 13800566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66500831 - 2¹⁸ = 66238687 is a prime.

It is a super-2 number, since 2×66500831² = 8844721047381122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66500794 and 66500803.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66500851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33250415 + 33250416.

It is an arithmetic number, because the mean of its divisors is an integer number (33250416).

Almost surely, 2^66500831 is an apocalyptic number.

66500831 is a deficient number, since it is larger than the sum of its proper divisors (1).

66500831 is an equidigital number, since it uses as much as digits as its factorization.

66500831 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 66500831 is about 8154.8041668700. The cubic root of 66500831 is about 405.1436385289.

The spelling of 66500831 in words is "sixty-six million, five hundred thousand, eight hundred thirty-one".