664571191911 has 16 divisors (see below), whose sum is σ = 966875539968. Its totient is φ = 402676030400.

The previous prime is 664571191903. The next prime is 664571191961. The reversal of 664571191911 is 119191175466.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 664571191911 - 2³ = 664571191903 is a prime.

It is a super-3 number, since 3×664571191911³ (a number of 36 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664571191961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2216646 + ... + 2498531.

It is an arithmetic number, because the mean of its divisors is an integer number (60429721248).

Almost surely, 2^664571191911 is an apocalyptic number.

664571191911 is a deficient number, since it is larger than the sum of its proper divisors (302304348057).

664571191911 is a wasteful number, since it uses less digits than its factorization.

664571191911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4719462.

The product of its digits is 408240, while the sum is 51.

The spelling of 664571191911 in words is "six hundred sixty-four billion, five hundred seventy-one million, one hundred ninety-one thousand, nine hundred eleven".