28064441661 has 4 divisors (see below), whose sum is σ = 37419255552. Its totient is φ = 18709627772.

The previous prime is 28064441627. The next prime is 28064441681. The reversal of 28064441661 is 16614446082.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 28064441661 - 2⁶ = 28064441597 is a prime.

It is a super-2 number, since 2×28064441661² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28064441681) 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 in 3 ways as a sum of consecutive naturals, for example, 4677406941 + ... + 4677406946.

It is an arithmetic number, because the mean of its divisors is an integer number (9354813888).

Almost surely, 2^28064441661 is an apocalyptic number.

It is an amenable number.

28064441661 is a deficient number, since it is larger than the sum of its proper divisors (9354813891).

28064441661 is an equidigital number, since it uses as much as digits as its factorization.

28064441661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9354813890.

The product of its (nonzero) digits is 221184, while the sum is 42.

The spelling of 28064441661 in words is "twenty-eight billion, sixty-four million, four hundred forty-one thousand, six hundred sixty-one".