665197109381 has 32 divisors (see below), whose sum is σ = 783684937728. Its totient is φ = 552756879360.

The previous prime is 665197109347. The next prime is 665197109383. The reversal of 665197109381 is 183901791566.

It is not a de Polignac number, because 665197109381 - 2²² = 665192915077 is a prime.

It is a super-2 number, since 2×665197109381² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665197109383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 48786341 + ... + 48799973.

It is an arithmetic number, because the mean of its divisors is an integer number (24490154304).

Almost surely, 2^665197109381 is an apocalyptic number.

It is an amenable number.

665197109381 is a deficient number, since it is larger than the sum of its proper divisors (118487828347).

665197109381 is a wasteful number, since it uses less digits than its factorization.

665197109381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14741.

The product of its (nonzero) digits is 2449440, while the sum is 56.

The spelling of 665197109381 in words is "six hundred sixty-five billion, one hundred ninety-seven million, one hundred nine thousand, three hundred eighty-one".