665606155555 has 16 divisors (see below), whose sum is σ = 879798576384. Its totient is φ = 479377421280.

The previous prime is 665606155469. The next prime is 665606155583. The reversal of 665606155555 is 555551606566.

It is a de Polignac number, because none of the positive numbers 2^k-665606155555 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (55).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 665606155496 and 665606155505.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58741569 + ... + 58752898.

It is an arithmetic number, because the mean of its divisors is an integer number (54987411024).

Almost surely, 2^665606155555 is an apocalyptic number.

665606155555 is a deficient number, since it is larger than the sum of its proper divisors (214192420829).

665606155555 is a wasteful number, since it uses less digits than its factorization.

665606155555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117494586.

The product of its (nonzero) digits is 20250000, while the sum is 55.

The spelling of 665606155555 in words is "six hundred sixty-five billion, six hundred six million, one hundred fifty-five thousand, five hundred fifty-five".