66736706025491 has 2 divisors, whose sum is σ = 66736706025492. Its totient is φ = 66736706025490.

The previous prime is 66736706025481. The next prime is 66736706025523. The reversal of 66736706025491 is 19452060763766.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66736706025491 - 2¹⁸ = 66736705763347 is a prime.

It is a super-2 number, since 2×66736706025491² (a number of 28 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (66736706025421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33368353012745 + 33368353012746.

It is an arithmetic number, because the mean of its divisors is an integer number (33368353012746).

Almost surely, 2^{66736706025491} is an apocalyptic number.

66736706025491 is a deficient number, since it is larger than the sum of its proper divisors (1).

66736706025491 is an equidigital number, since it uses as much as digits as its factorization.

66736706025491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 68584320, while the sum is 62.

The spelling of 66736706025491 in words is "sixty-six trillion, seven hundred thirty-six billion, seven hundred six million, twenty-five thousand, four hundred ninety-one".