66997159 has 4 divisors (see below), whose sum is σ = 67239304. Its totient is φ = 66755016.

The previous prime is 66997129. The next prime is 66997207. The reversal of 66997159 is 95179966.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66997159 - 2⁵ = 66997127 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 (66997109) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120657 + ... + 121210.

It is an arithmetic number, because the mean of its divisors is an integer number (16809826).

Almost surely, 2^66997159 is an apocalyptic number.

66997159 is a deficient number, since it is larger than the sum of its proper divisors (242145).

66997159 is a wasteful number, since it uses less digits than its factorization.

66997159 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242144.

The product of its digits is 918540, while the sum is 52.

The square root of 66997159 is about 8185.1792283370. The cubic root of 66997159 is about 406.1490692380.

The spelling of 66997159 in words is "sixty-six million, nine hundred ninety-seven thousand, one hundred fifty-nine".