665434548381 has 4 divisors (see below), whose sum is σ = 887246064512. Its totient is φ = 443623032252.

The previous prime is 665434548379. The next prime is 665434548421. The reversal of 665434548381 is 183845434566.

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 not a de Polignac number, because 665434548381 - 2¹ = 665434548379 is a prime.

It is a super-2 number, since 2×665434548381² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665434548301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110905758061 + ... + 110905758066.

It is an arithmetic number, because the mean of its divisors is an integer number (221811516128).

Almost surely, 2^665434548381 is an apocalyptic number.

It is an amenable number.

665434548381 is a deficient number, since it is larger than the sum of its proper divisors (221811516131).

665434548381 is a wasteful number, since it uses less digits than its factorization.

665434548381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221811516130.

The product of its digits is 33177600, while the sum is 57.

The spelling of 665434548381 in words is "six hundred sixty-five billion, four hundred thirty-four million, five hundred forty-eight thousand, three hundred eighty-one".