665857481 has 4 divisors (see below), whose sum is σ = 666561552. Its totient is φ = 665153412.

The previous prime is 665857477. The next prime is 665857483. The reversal of 665857481 is 184758566.

665857481 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, and also an emirpimes, since its reverse is a distinct semiprime: 184758566 = 2 ⋅92379283.

It is a cyclic number.

It is not a de Polignac number, because 665857481 - 2² = 665857477 is a prime.

It is a super-2 number, since 2×665857481² = 886732370007330722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665857483) 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, 350615 + ... + 352508.

It is an arithmetic number, because the mean of its divisors is an integer number (166640388).

Almost surely, 2^665857481 is an apocalyptic number.

It is an amenable number.

665857481 is a deficient number, since it is larger than the sum of its proper divisors (704071).

665857481 is an equidigital number, since it uses as much as digits as its factorization.

665857481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 704070.

The product of its digits is 1612800, while the sum is 50.

The square root of 665857481 is about 25804.2144038527. The cubic root of 665857481 is about 873.2268772434.

The spelling of 665857481 in words is "six hundred sixty-five million, eight hundred fifty-seven thousand, four hundred eighty-one".