66544999 has 4 divisors (see below), whose sum is σ = 67023880. Its totient is φ = 66066120.

The previous prime is 66544993. The next prime is 66545023. The reversal of 66544999 is 99944566.

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 66544999 - 2⁵ = 66544967 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 (66544993) 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, 239232 + ... + 239509.

It is an arithmetic number, because the mean of its divisors is an integer number (16755970).

Almost surely, 2^66544999 is an apocalyptic number.

66544999 is a deficient number, since it is larger than the sum of its proper divisors (478881).

66544999 is a wasteful number, since it uses less digits than its factorization.

66544999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478880.

The product of its digits is 2099520, while the sum is 52.

The square root of 66544999 is about 8157.5118142728. The cubic root of 66544999 is about 405.2333137193.

The spelling of 66544999 in words is "sixty-six million, five hundred forty-four thousand, nine hundred ninety-nine".