66634397 has 2 divisors, whose sum is σ = 66634398. Its totient is φ = 66634396.

The previous prime is 66634333. The next prime is 66634417. The reversal of 66634397 is 79343666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 53860921 + 12773476 = 7339^2 + 3574^2 .

It is a cyclic number.

It is not a de Polignac number, because 66634397 - 2⁶ = 66634333 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 (66634597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33317198 + 33317199.

It is an arithmetic number, because the mean of its divisors is an integer number (33317199).

Almost surely, 2^66634397 is an apocalyptic number.

It is an amenable number.

66634397 is a deficient number, since it is larger than the sum of its proper divisors (1).

66634397 is an equidigital number, since it uses as much as digits as its factorization.

66634397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 489888, while the sum is 44.

The square root of 66634397 is about 8162.9894646508. The cubic root of 66634397 is about 405.4146989357.

The spelling of 66634397 in words is "sixty-six million, six hundred thirty-four thousand, three hundred ninety-seven".