66997061 has 2 divisors, whose sum is σ = 66997062. Its totient is φ = 66997060.

The previous prime is 66997033. The next prime is 66997069. The reversal of 66997061 is 16079966.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51394561 + 15602500 = 7169^2 + 3950^2 .

It is a cyclic number.

It is not a de Polignac number, because 66997061 - 2⁶ = 66996997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66997069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33498530 + 33498531.

It is an arithmetic number, because the mean of its divisors is an integer number (33498531).

Almost surely, 2^66997061 is an apocalyptic number.

It is an amenable number.

66997061 is a deficient number, since it is larger than the sum of its proper divisors (1).

66997061 is an equidigital number, since it uses as much as digits as its factorization.

66997061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 122472, while the sum is 44.

The square root of 66997061 is about 8185.1732419051. The cubic root of 66997061 is about 406.1488712066.

The spelling of 66997061 in words is "sixty-six million, nine hundred ninety-seven thousand, sixty-one".