66601237823999 has 4 divisors (see below), whose sum is σ = 66689218323864. Its totient is φ = 66513257324136.

The previous prime is 66601237823957. The next prime is 66601237824047. The reversal of 66601237823999 is 99932873210666.

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 66601237823999 - 2²⁴ = 66601221046783 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 (66601237823929) 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, 43990248797 + ... + 43990250310.

It is an arithmetic number, because the mean of its divisors is an integer number (16672304580966).

Almost surely, 2^{66601237823999} is an apocalyptic number.

66601237823999 is a deficient number, since it is larger than the sum of its proper divisors (87980499865).

66601237823999 is an equidigital number, since it uses as much as digits as its factorization.

66601237823999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87980499864.

The product of its (nonzero) digits is 317447424, while the sum is 71.

The spelling of 66601237823999 in words is "sixty-six trillion, six hundred one billion, two hundred thirty-seven million, eight hundred twenty-three thousand, nine hundred ninety-nine".