664578522547 has 4 divisors (see below), whose sum is σ = 665463448096. Its totient is φ = 663693597000.

The previous prime is 664578522541. The next prime is 664578522589. The reversal of 664578522547 is 745225875466.

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 664578522547 - 2²³ = 664570133939 is a prime.

It is a super-2 number, since 2×664578522547² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664578522541) 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, 442461648 + ... + 442463149.

It is an arithmetic number, because the mean of its divisors is an integer number (166365862024).

Almost surely, 2^664578522547 is an apocalyptic number.

664578522547 is a deficient number, since it is larger than the sum of its proper divisors (884925549).

664578522547 is an equidigital number, since it uses as much as digits as its factorization.

664578522547 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 884925548.

The product of its digits is 112896000, while the sum is 61.

The spelling of 664578522547 in words is "six hundred sixty-four billion, five hundred seventy-eight million, five hundred twenty-two thousand, five hundred forty-seven".