28313531 has 2 divisors, whose sum is σ = 28313532. Its totient is φ = 28313530.

The previous prime is 28313503. The next prime is 28313533. The reversal of 28313531 is 13531382.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28313531 - 2¹⁴ = 28297147 is a prime.

It is a super-2 number, since 2×28313531² = 1603312075375922, which contains 22 as substring.

Together with 28313533, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28313531.

It is not a weakly prime, because it can be changed into another prime (28313533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14156765 + 14156766.

It is an arithmetic number, because the mean of its divisors is an integer number (14156766).

Almost surely, 2^28313531 is an apocalyptic number.

28313531 is a deficient number, since it is larger than the sum of its proper divisors (1).

28313531 is an equidigital number, since it uses as much as digits as its factorization.

28313531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2160, while the sum is 26.

The square root of 28313531 is about 5321.0460437775. The cubic root of 28313531 is about 304.7881032906.

The spelling of 28313531 in words is "twenty-eight million, three hundred thirteen thousand, five hundred thirty-one".