66632261 has 2 divisors, whose sum is σ = 66632262. Its totient is φ = 66632260.

The previous prime is 66632249. The next prime is 66632263. The reversal of 66632261 is 16223666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49773025 + 16859236 = 7055^2 + 4106^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66632261 is a prime.

Together with 66632263, 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 (66632263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33316130 + 33316131.

It is an arithmetic number, because the mean of its divisors is an integer number (33316131).

Almost surely, 2^66632261 is an apocalyptic number.

It is an amenable number.

66632261 is a deficient number, since it is larger than the sum of its proper divisors (1).

66632261 is an equidigital number, since it uses as much as digits as its factorization.

66632261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 32.

The square root of 66632261 is about 8162.8586291813. The cubic root of 66632261 is about 405.4103669636.

The spelling of 66632261 in words is "sixty-six million, six hundred thirty-two thousand, two hundred sixty-one".