66275381 has 2 divisors, whose sum is σ = 66275382. Its totient is φ = 66275380.

The previous prime is 66275371. The next prime is 66275383. The reversal of 66275381 is 18357266.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36409156 + 29866225 = 6034^2 + 5465^2 .

It is a cyclic number.

It is not a de Polignac number, because 66275381 - 2⁶ = 66275317 is a prime.

It is a super-2 number, since 2×66275381² = 8784852253390322, which contains 22 as substring.

Together with 66275383, 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 (66275383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33137690 + 33137691.

It is an arithmetic number, because the mean of its divisors is an integer number (33137691).

Almost surely, 2^66275381 is an apocalyptic number.

It is an amenable number.

66275381 is a deficient number, since it is larger than the sum of its proper divisors (1).

66275381 is an equidigital number, since it uses as much as digits as its factorization.

66275381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60480, while the sum is 38.

The square root of 66275381 is about 8140.9692911839. The cubic root of 66275381 is about 404.6852831162.

The spelling of 66275381 in words is "sixty-six million, two hundred seventy-five thousand, three hundred eighty-one".