28523881 has 2 divisors, whose sum is σ = 28523882. Its totient is φ = 28523880.

The previous prime is 28523867. The next prime is 28523899. The reversal of 28523881 is 18832582.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28515600 + 8281 = 5340^2 + 91^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28523881 is a prime.

It is a super-2 number, since 2×28523881² = 1627223574604322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28523881.

It is not a weakly prime, because it can be changed into another prime (28523821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14261940 + 14261941.

It is an arithmetic number, because the mean of its divisors is an integer number (14261941).

Almost surely, 2^28523881 is an apocalyptic number.

It is an amenable number.

28523881 is a deficient number, since it is larger than the sum of its proper divisors (1).

28523881 is an equidigital number, since it uses as much as digits as its factorization.

28523881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30720, while the sum is 37.

The square root of 28523881 is about 5340.7753182473. The cubic root of 28523881 is about 305.5410302198.

The spelling of 28523881 in words is "twenty-eight million, five hundred twenty-three thousand, eight hundred eighty-one".