665855321834 has 4 divisors (see below), whose sum is σ = 998782982754. Its totient is φ = 332927660916.

The previous prime is 665855321779. The next prime is 665855321837. The reversal of 665855321834 is 438123558566.

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

It can be written as a sum of positive squares in only one way, i.e., 616813890625 + 49041431209 = 785375^2 + 221453^2 .

It is a super-2 number, since 2×665855321834² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 665855321834.

It is not an unprimeable number, because it can be changed into a prime (665855321837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166463830457 + ... + 166463830460.

Almost surely, 2^665855321834 is an apocalyptic number.

665855321834 is a deficient number, since it is larger than the sum of its proper divisors (332927660920).

665855321834 is a wasteful number, since it uses less digits than its factorization.

665855321834 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332927660919.

The product of its digits is 20736000, while the sum is 56.

The spelling of 665855321834 in words is "six hundred sixty-five billion, eight hundred fifty-five million, three hundred twenty-one thousand, eight hundred thirty-four".