28386661 has 4 divisors (see below), whose sum is σ = 28419552. Its totient is φ = 28353772.

The previous prime is 28386649. The next prime is 28386671. The reversal of 28386661 is 16668382.

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 28386661 - 2⁵ = 28386629 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 (28386671) 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, 15115 + ... + 16888.

It is an arithmetic number, because the mean of its divisors is an integer number (7104888).

Almost surely, 2^28386661 is an apocalyptic number.

It is an amenable number.

28386661 is a deficient number, since it is larger than the sum of its proper divisors (32891).

28386661 is an equidigital number, since it uses as much as digits as its factorization.

28386661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32890.

The product of its digits is 82944, while the sum is 40.

The square root of 28386661 is about 5327.9133814280. The cubic root of 28386661 is about 305.0502864323.

The spelling of 28386661 in words is "twenty-eight million, three hundred eighty-six thousand, six hundred sixty-one".