66725861 has 2 divisors, whose sum is σ = 66725862. Its totient is φ = 66725860.

The previous prime is 66725851. The next prime is 66725863. The reversal of 66725861 is 16852766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65529025 + 1196836 = 8095^2 + 1094^2 .

It is a cyclic number.

It is not a de Polignac number, because 66725861 - 2¹⁴ = 66709477 is a prime.

It is a super-3 number, since 3×66725861³ (a number of 24 digits) contains 333 as substring.

Together with 66725863, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66725863) 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, 33362930 + 33362931.

It is an arithmetic number, because the mean of its divisors is an integer number (33362931).

Almost surely, 2^66725861 is an apocalyptic number.

It is an amenable number.

66725861 is a deficient number, since it is larger than the sum of its proper divisors (1).

66725861 is an equidigital number, since it uses as much as digits as its factorization.

66725861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120960, while the sum is 41.

The square root of 66725861 is about 8168.5899027923. The cubic root of 66725861 is about 405.6001081668.

The spelling of 66725861 in words is "sixty-six million, seven hundred twenty-five thousand, eight hundred sixty-one".