28275251 has 4 divisors (see below), whose sum is σ = 28549872. Its totient is φ = 28000632.

The previous prime is 28275239. The next prime is 28275307. The reversal of 28275251 is 15257282.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28275251 is a prime.

It is a super-2 number, since 2×28275251² = 1598979638226002, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28271251) 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, 137156 + ... + 137361.

It is an arithmetic number, because the mean of its divisors is an integer number (7137468).

Almost surely, 2^28275251 is an apocalyptic number.

28275251 is a deficient number, since it is larger than the sum of its proper divisors (274621).

28275251 is a wasteful number, since it uses less digits than its factorization.

28275251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274620.

The product of its digits is 11200, while the sum is 32.

The square root of 28275251 is about 5317.4477900587. The cubic root of 28275251 is about 304.6506831219.

The spelling of 28275251 in words is "twenty-eight million, two hundred seventy-five thousand, two hundred fifty-one".