66997013 has 2 divisors, whose sum is σ = 66997014. Its totient is φ = 66997012.

The previous prime is 66997009. The next prime is 66997031. The reversal of 66997013 is 31079966.

It is a happy number.

Together with next prime (66997031) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46267204 + 20729809 = 6802^2 + 4553^2 .

It is a cyclic number.

It is not a de Polignac number, because 66997013 - 2² = 66997009 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66997033) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33498506 + 33498507.

It is an arithmetic number, because the mean of its divisors is an integer number (33498507).

Almost surely, 2^66997013 is an apocalyptic number.

It is an amenable number.

66997013 is a deficient number, since it is larger than the sum of its proper divisors (1).

66997013 is an equidigital number, since it uses as much as digits as its factorization.

66997013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 61236, while the sum is 41.

The square root of 66997013 is about 8185.1703097736. The cubic root of 66997013 is about 406.1487742115.

The spelling of 66997013 in words is "sixty-six million, nine hundred ninety-seven thousand, thirteen".