28355551 has 4 divisors (see below), whose sum is σ = 32406352. Its totient is φ = 24304752.

The previous prime is 28355531. The next prime is 28355563. The reversal of 28355551 is 15555382.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28355551 - 2⁹ = 28355039 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 (28355501) 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, 2025390 + ... + 2025403.

It is an arithmetic number, because the mean of its divisors is an integer number (8101588).

Almost surely, 2^28355551 is an apocalyptic number.

28355551 is a deficient number, since it is larger than the sum of its proper divisors (4050801).

28355551 is an equidigital number, since it uses as much as digits as its factorization.

28355551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4050800.

The product of its digits is 30000, while the sum is 34.

The square root of 28355551 is about 5324.9930516387. The cubic root of 28355551 is about 304.9388070373.

The spelling of 28355551 in words is "twenty-eight million, three hundred fifty-five thousand, five hundred fifty-one".