66091797 has 12 divisors (see below), whose sum is σ = 95680780. Its totient is φ = 43962048.

The previous prime is 66091793. The next prime is 66091799. The reversal of 66091797 is 79719066.

It can be written as a sum of positive squares in 2 ways, for example, as 38118276 + 27973521 = 6174^2 + 5289^2 .

It is not a de Polignac number, because 66091797 - 2² = 66091793 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66091793) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3922 + ... + 12147.

Almost surely, 2^66091797 is an apocalyptic number.

It is an amenable number.

66091797 is a deficient number, since it is larger than the sum of its proper divisors (29588983).

66091797 is a wasteful number, since it uses less digits than its factorization.

66091797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16532 (or 16529 counting only the distinct ones).

The product of its (nonzero) digits is 142884, while the sum is 45.

The square root of 66091797 is about 8129.6861563039. The cubic root of 66091797 is about 404.3112757247.

The spelling of 66091797 in words is "sixty-six million, ninety-one thousand, seven hundred ninety-seven".