28277531 has 4 divisors (see below), whose sum is σ = 28935192. Its totient is φ = 27619872.

The previous prime is 28277527. The next prime is 28277533. The reversal of 28277531 is 13577282.

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 28277531 - 2² = 28277527 is a prime.

It is a super-2 number, since 2×28277531² = 1599237518911922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28277491 and 28277500.

It is not an unprimeable number, because it can be changed into a prime (28277533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 328766 + ... + 328851.

It is an arithmetic number, because the mean of its divisors is an integer number (7233798).

Almost surely, 2^28277531 is an apocalyptic number.

28277531 is a deficient number, since it is larger than the sum of its proper divisors (657661).

28277531 is an equidigital number, since it uses as much as digits as its factorization.

28277531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 657660.

The product of its digits is 23520, while the sum is 35.

The square root of 28277531 is about 5317.6621743018. The cubic root of 28277531 is about 304.6588714947.

The spelling of 28277531 in words is "twenty-eight million, two hundred seventy-seven thousand, five hundred thirty-one".