28038561 has 4 divisors (see below), whose sum is σ = 37384752. Its totient is φ = 18692372.

The previous prime is 28038551. The next prime is 28038583. The reversal of 28038561 is 16583082.

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 28038561 - 2²³ = 19649953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28038551) 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, 4673091 + ... + 4673096.

It is an arithmetic number, because the mean of its divisors is an integer number (9346188).

Almost surely, 2^28038561 is an apocalyptic number.

It is an amenable number.

28038561 is a deficient number, since it is larger than the sum of its proper divisors (9346191).

28038561 is an equidigital number, since it uses as much as digits as its factorization.

28038561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9346190.

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 28038561 is about 5295.1450405064. The cubic root of 28038561 is about 303.7982307535.

The spelling of 28038561 in words is "twenty-eight million, thirty-eight thousand, five hundred sixty-one".