66187997 has 8 divisors (see below), whose sum is σ = 69417600. Its totient is φ = 62987760.

The previous prime is 66187993. The next prime is 66188011. The reversal of 66187997 is 79978166.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66187997 - 2² = 66187993 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 (66187993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2654 + ... + 11807.

It is an arithmetic number, because the mean of its divisors is an integer number (8677200).

Almost surely, 2^66187997 is an apocalyptic number.

It is an amenable number.

66187997 is a deficient number, since it is larger than the sum of its proper divisors (3229603).

66187997 is a wasteful number, since it uses less digits than its factorization.

66187997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14683.

The product of its digits is 1143072, while the sum is 53.

The square root of 66187997 is about 8135.6005924578. The cubic root of 66187997 is about 404.5073458909.

The spelling of 66187997 in words is "sixty-six million, one hundred eighty-seven thousand, nine hundred ninety-seven".