665550501061 has 4 divisors (see below), whose sum is σ = 694487479392. Its totient is φ = 636613522732.

The previous prime is 665550501029. The next prime is 665550501101. The reversal of 665550501061 is 160105055566.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 665550501061 - 2⁵ = 665550501029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665550901061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14468489131 + ... + 14468489176.

It is an arithmetic number, because the mean of its divisors is an integer number (173621869848).

Almost surely, 2^665550501061 is an apocalyptic number.

It is an amenable number.

665550501061 is a deficient number, since it is larger than the sum of its proper divisors (28936978331).

665550501061 is a wasteful number, since it uses less digits than its factorization.

665550501061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28936978330.

The product of its (nonzero) digits is 135000, while the sum is 40.

It can be divided in two parts, 665550 and 501061, that added together give a palindrome (1166611).

The spelling of 665550501061 in words is "six hundred sixty-five billion, five hundred fifty million, five hundred one thousand, sixty-one".