665472881 has 2 divisors, whose sum is σ = 665472882. Its totient is φ = 665472880.

The previous prime is 665472839. The next prime is 665472901. The reversal of 665472881 is 188274566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 662290225 + 3182656 = 25735^2 + 1784^2 .

It is a cyclic number.

It is not a de Polignac number, because 665472881 - 2⁶ = 665472817 is a prime.

It is a super-2 number, since 2×665472881² = 885708310692880322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (665472281) 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 as a sum of consecutive naturals, namely, 332736440 + 332736441.

It is an arithmetic number, because the mean of its divisors is an integer number (332736441).

Almost surely, 2^665472881 is an apocalyptic number.

It is an amenable number.

665472881 is a deficient number, since it is larger than the sum of its proper divisors (1).

665472881 is an equidigital number, since it uses as much as digits as its factorization.

665472881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 645120, while the sum is 47.

The square root of 665472881 is about 25796.7610563807. The cubic root of 665472881 is about 873.0587192674.

The spelling of 665472881 in words is "six hundred sixty-five million, four hundred seventy-two thousand, eight hundred eighty-one".