28388661407 has 4 divisors (see below), whose sum is σ = 28397795640. Its totient is φ = 28379527176.

The previous prime is 28388661391. The next prime is 28388661481. The reversal of 28388661407 is 70416688382.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 70416688382 = 2 ⋅35208344191.

It is a cyclic number.

It is not a de Polignac number, because 28388661407 - 2⁴ = 28388661391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28388664407) 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, 4562453 + ... + 4568670.

It is an arithmetic number, because the mean of its divisors is an integer number (7099448910).

Almost surely, 2^28388661407 is an apocalyptic number.

28388661407 is a deficient number, since it is larger than the sum of its proper divisors (9134233).

28388661407 is an equidigital number, since it uses as much as digits as its factorization.

28388661407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9134232.

The product of its (nonzero) digits is 3096576, while the sum is 53.

The spelling of 28388661407 in words is "twenty-eight billion, three hundred eighty-eight million, six hundred sixty-one thousand, four hundred seven".