66109397 has 2 divisors, whose sum is σ = 66109398. Its totient is φ = 66109396.

The previous prime is 66109339. The next prime is 66109409. The reversal of 66109397 is 79390166.

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., 37283236 + 28826161 = 6106^2 + 5369^2 .

It is a cyclic number.

It is not a de Polignac number, because 66109397 - 2²² = 61915093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66109997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33054698 + 33054699.

It is an arithmetic number, because the mean of its divisors is an integer number (33054699).

Almost surely, 2^66109397 is an apocalyptic number.

It is an amenable number.

66109397 is a deficient number, since it is larger than the sum of its proper divisors (1).

66109397 is an equidigital number, since it uses as much as digits as its factorization.

66109397 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 66109397 is about 8130.7685368605. The cubic root of 66109397 is about 404.3471614030.

The spelling of 66109397 in words is "sixty-six million, one hundred nine thousand, three hundred ninety-seven".