66662261 has 2 divisors, whose sum is σ = 66662262. Its totient is φ = 66662260.

The previous prime is 66662237. The next prime is 66662291. The reversal of 66662261 is 16226666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60062500 + 6599761 = 7750^2 + 2569^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66662261 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66662221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33331130 + 33331131.

It is an arithmetic number, because the mean of its divisors is an integer number (33331131).

Almost surely, 2^66662261 is an apocalyptic number.

It is an amenable number.

66662261 is a deficient number, since it is larger than the sum of its proper divisors (1).

66662261 is an equidigital number, since it uses as much as digits as its factorization.

66662261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 35.

The square root of 66662261 is about 8164.6960139371. The cubic root of 66662261 is about 405.4712007899.

The spelling of 66662261 in words is "sixty-six million, six hundred sixty-two thousand, two hundred sixty-one".