66616610997 has 4 divisors (see below), whose sum is σ = 88822148000. Its totient is φ = 44411073996.

The previous prime is 66616610987. The next prime is 66616611007. The reversal of 66616610997 is 79901661666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (66616610987) and next prime (66616611007).

It is not a de Polignac number, because 66616610997 - 2⁸ = 66616610741 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 (66616610927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11102768497 + ... + 11102768502.

It is an arithmetic number, because the mean of its divisors is an integer number (22205537000).

Almost surely, 2^66616610997 is an apocalyptic number.

It is an amenable number.

66616610997 is a deficient number, since it is larger than the sum of its proper divisors (22205537003).

66616610997 is a wasteful number, since it uses less digits than its factorization.

66616610997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22205537002.

The product of its (nonzero) digits is 4408992, while the sum is 57.

The spelling of 66616610997 in words is "sixty-six billion, six hundred sixteen million, six hundred ten thousand, nine hundred ninety-seven".