66937186891 has 2 divisors, whose sum is σ = 66937186892. Its totient is φ = 66937186890.

The previous prime is 66937186871. The next prime is 66937186907. The reversal of 66937186891 is 19868173966.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66937186891 - 2⁵ = 66937186859 is a prime.

It is not a weakly prime, because it can be changed into another prime (66937186861) 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, 33468593445 + 33468593446.

It is an arithmetic number, because the mean of its divisors is an integer number (33468593446).

Almost surely, 2^66937186891 is an apocalyptic number.

66937186891 is a deficient number, since it is larger than the sum of its proper divisors (1).

66937186891 is an equidigital number, since it uses as much as digits as its factorization.

66937186891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23514624, while the sum is 64.

It can be divided in two parts, 66937 and 186891, that added together give a triangular number (253828 = T₇₁₂).

The spelling of 66937186891 in words is "sixty-six billion, nine hundred thirty-seven million, one hundred eighty-six thousand, eight hundred ninety-one".