28012681 has 2 divisors, whose sum is σ = 28012682. Its totient is φ = 28012680.

The previous prime is 28012667. The next prime is 28012693. The reversal of 28012681 is 18621082.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26214400 + 1798281 = 5120^2 + 1341^2 .

It is a cyclic number.

It is not a de Polignac number, because 28012681 - 2¹³ = 28004489 is a prime.

It is a super-2 number, since 2×28012681² = 1569420593615522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28012181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14006340 + 14006341.

It is an arithmetic number, because the mean of its divisors is an integer number (14006341).

Almost surely, 2^28012681 is an apocalyptic number.

It is an amenable number.

28012681 is a deficient number, since it is larger than the sum of its proper divisors (1).

28012681 is an equidigital number, since it uses as much as digits as its factorization.

28012681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 28012681 is about 5292.7007283617. The cubic root of 28012681 is about 303.7047319174.

The spelling of 28012681 in words is "twenty-eight million, twelve thousand, six hundred eighty-one".