65669881 has 4 divisors (see below), whose sum is σ = 65686132. Its totient is φ = 65653632.

The previous prime is 65669869. The next prime is 65669893. The reversal of 65669881 is 18896656.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (65669869) and next prime (65669893).

It can be written as a sum of positive squares in 2 ways, for example, as 49829481 + 15840400 = 7059^2 + 3980^2 .

It is a cyclic number.

It is not a de Polignac number, because 65669881 - 2¹⁹ = 65145593 is a prime.

It is a super-2 number, since 2×65669881² = 8625066541108322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65669831) 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, 3181 + ... + 11893.

It is an arithmetic number, because the mean of its divisors is an integer number (16421533).

Almost surely, 2^65669881 is an apocalyptic number.

It is an amenable number.

65669881 is a deficient number, since it is larger than the sum of its proper divisors (16251).

65669881 is an equidigital number, since it uses as much as digits as its factorization.

65669881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16250.

The product of its digits is 622080, while the sum is 49.

The square root of 65669881 is about 8103.6955150104. The cubic root of 65669881 is about 403.4490926677.

The spelling of 65669881 in words is "sixty-five million, six hundred sixty-nine thousand, eight hundred eighty-one".