28317881 has 2 divisors, whose sum is σ = 28317882. Its totient is φ = 28317880.

The previous prime is 28317823. The next prime is 28317907. The reversal of 28317881 is 18871382.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21114025 + 7203856 = 4595^2 + 2684^2 .

It is a cyclic number.

It is not a de Polignac number, because 28317881 - 2²² = 24123577 is a prime.

It is a super-2 number, since 2×28317881² = 1603804768660322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28317781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14158940 + 14158941.

It is an arithmetic number, because the mean of its divisors is an integer number (14158941).

Almost surely, 2^28317881 is an apocalyptic number.

It is an amenable number.

28317881 is a deficient number, since it is larger than the sum of its proper divisors (1).

28317881 is an equidigital number, since it uses as much as digits as its factorization.

28317881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21504, while the sum is 38.

The square root of 28317881 is about 5321.4547822940. The cubic root of 28317881 is about 304.8037113798.

The spelling of 28317881 in words is "twenty-eight million, three hundred seventeen thousand, eight hundred eighty-one".