28510681 has 2 divisors, whose sum is σ = 28510682. Its totient is φ = 28510680.

The previous prime is 28510673. The next prime is 28510687. The reversal of 28510681 is 18601582.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20331081 + 8179600 = 4509^2 + 2860^2 .

It is a cyclic number.

It is not a de Polignac number, because 28510681 - 2³ = 28510673 is a prime.

It is a super-2 number, since 2×28510681² = 1625717862167522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28510687) 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, 14255340 + 14255341.

It is an arithmetic number, because the mean of its divisors is an integer number (14255341).

Almost surely, 2^28510681 is an apocalyptic number.

It is an amenable number.

28510681 is a deficient number, since it is larger than the sum of its proper divisors (1).

28510681 is an equidigital number, since it uses as much as digits as its factorization.

28510681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3840, while the sum is 31.

The square root of 28510681 is about 5339.5393996112. The cubic root of 28510681 is about 305.4938911939.

Subtracting from 28510681 its reverse (18601582), we obtain a palindrome (9909099).

The spelling of 28510681 in words is "twenty-eight million, five hundred ten thousand, six hundred eighty-one".