66116551 has 2 divisors, whose sum is σ = 66116552. Its totient is φ = 66116550.

The previous prime is 66116543. The next prime is 66116563. The reversal of 66116551 is 15561166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66116551 - 2³ = 66116543 is a prime.

It is a super-2 number, since 2×66116551² = 8742796632271202, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66116051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33058275 + 33058276.

It is an arithmetic number, because the mean of its divisors is an integer number (33058276).

Almost surely, 2^66116551 is an apocalyptic number.

66116551 is a deficient number, since it is larger than the sum of its proper divisors (1).

66116551 is an equidigital number, since it uses as much as digits as its factorization.

66116551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5400, while the sum is 31.

The square root of 66116551 is about 8131.2084587717. The cubic root of 66116551 is about 404.3617462951.

The spelling of 66116551 in words is "sixty-six million, one hundred sixteen thousand, five hundred fifty-one".