665525565525566 has 4 divisors (see below), whose sum is σ = 998288348288352. Its totient is φ = 332762782762782.

The previous prime is 665525565525529. The next prime is 665525565525577.

665525565525566 is nontrivially palindromic in base 10.

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

It is a junction number, because it is equal to n+sod(n) for n = 665525565525493 and 665525565525502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166381391381390 + ... + 166381391381393.

It is an arithmetic number, because the mean of its divisors is an integer number (249572087072088).

Almost surely, 2^{665525565525566} is an apocalyptic number.

665525565525566 is a deficient number, since it is larger than the sum of its proper divisors (332762782762786).

665525565525566 is a wasteful number, since it uses less digits than its factorization.

665525565525566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332762782762785.

The product of its digits is 12150000000, while the sum is 74.

The spelling of 665525565525566 in words is "six hundred sixty-five trillion, five hundred twenty-five billion, five hundred sixty-five million, five hundred twenty-five thousand, five hundred sixty-six".