666544052540401 has 8 divisors (see below), whose sum is σ = 801857506815680. Its totient is φ = 541253817100368.

The previous prime is 666544052540347. The next prime is 666544052540489. The reversal of 666544052540401 is 104045250445666.

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 666544052540401 - 2⁷ = 666544052540273 is a prime.

It is not an unprimeable number, because it can be changed into a prime (666544052540101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2505804708666 + ... + 2505804708931.

It is an arithmetic number, because the mean of its divisors is an integer number (100232188351960).

Almost surely, 2^{666544052540401} is an apocalyptic number.

It is an amenable number.

666544052540401 is a deficient number, since it is larger than the sum of its proper divisors (135313454275279).

666544052540401 is a wasteful number, since it uses less digits than its factorization.

666544052540401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5011609417623.

The product of its (nonzero) digits is 13824000, while the sum is 52.

The spelling of 666544052540401 in words is "six hundred sixty-six trillion, five hundred forty-four billion, fifty-two million, five hundred forty thousand, four hundred one".