665474881 has 2 divisors, whose sum is σ = 665474882. Its totient is φ = 665474880.

The previous prime is 665474879. The next prime is 665474941. The reversal of 665474881 is 188474566.

665474881 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 609299856 + 56175025 = 24684^2 + 7495^2 .

It is a cyclic number.

It is not a de Polignac number, because 665474881 - 2¹ = 665474879 is a prime.

It is a super-2 number, since 2×665474881² = 885713634483928322, which contains 22 as substring.

Together with 665474879, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (665472881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332737440 + 332737441.

It is an arithmetic number, because the mean of its divisors is an integer number (332737441).

Almost surely, 2^665474881 is an apocalyptic number.

It is an amenable number.

665474881 is a deficient number, since it is larger than the sum of its proper divisors (1).

665474881 is an equidigital number, since it uses as much as digits as its factorization.

665474881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1290240, while the sum is 49.

The square root of 665474881 is about 25796.7998209080. The cubic root of 665474881 is about 873.0595938914.

The spelling of 665474881 in words is "six hundred sixty-five million, four hundred seventy-four thousand, eight hundred eighty-one".