664551454664271 has 4 divisors (see below), whose sum is σ = 886068606219032. Its totient is φ = 443034303109512.

The previous prime is 664551454664267. The next prime is 664551454664291. The reversal of 664551454664271 is 172466454155466.

It is a happy number.

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

It is not a de Polignac number, because 664551454664271 - 2² = 664551454664267 is a prime.

It is a super-2 number, since 2×664551454664271² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664551454664291) 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 3 ways as a sum of consecutive naturals, for example, 110758575777376 + ... + 110758575777381.

It is an arithmetic number, because the mean of its divisors is an integer number (221517151554758).

Almost surely, 2^{664551454664271} is an apocalyptic number.

664551454664271 is a deficient number, since it is larger than the sum of its proper divisors (221517151554761).

664551454664271 is a wasteful number, since it uses less digits than its factorization.

664551454664271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221517151554760.

The product of its digits is 580608000, while the sum is 66.

The spelling of 664551454664271 in words is "six hundred sixty-four trillion, five hundred fifty-one billion, four hundred fifty-four million, six hundred sixty-four thousand, two hundred seventy-one".