66977257 has 2 divisors, whose sum is σ = 66977258. Its totient is φ = 66977256.

The previous prime is 66977249. The next prime is 66977279. The reversal of 66977257 is 75277966.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38204761 + 28772496 = 6181^2 + 5364^2 .

It is a cyclic number.

It is not a de Polignac number, because 66977257 - 2³ = 66977249 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66977257.

It is not a weakly prime, because it can be changed into another prime (66977857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33488628 + 33488629.

It is an arithmetic number, because the mean of its divisors is an integer number (33488629).

Almost surely, 2^66977257 is an apocalyptic number.

It is an amenable number.

66977257 is a deficient number, since it is larger than the sum of its proper divisors (1).

66977257 is an equidigital number, since it uses as much as digits as its factorization.

66977257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1111320, while the sum is 49.

The square root of 66977257 is about 8183.9634041215. The cubic root of 66977257 is about 406.1088487300.

The spelling of 66977257 in words is "sixty-six million, nine hundred seventy-seven thousand, two hundred fifty-seven".