28553561 has 4 divisors (see below), whose sum is σ = 30056400. Its totient is φ = 27050724.

The previous prime is 28553549. The next prime is 28553563. The reversal of 28553561 is 16535582.

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 28553561 - 2¹⁴ = 28537177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28553563) 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, 751391 + ... + 751428.

It is an arithmetic number, because the mean of its divisors is an integer number (7514100).

Almost surely, 2^28553561 is an apocalyptic number.

It is an amenable number.

28553561 is a deficient number, since it is larger than the sum of its proper divisors (1502839).

28553561 is a wasteful number, since it uses less digits than its factorization.

28553561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1502838.

The product of its digits is 36000, while the sum is 35.

The square root of 28553561 is about 5343.5532185990. The cubic root of 28553561 is about 305.6469685183.

The spelling of 28553561 in words is "twenty-eight million, five hundred fifty-three thousand, five hundred sixty-one".