28658681 has 2 divisors, whose sum is σ = 28658682. Its totient is φ = 28658680.

The previous prime is 28658677. The next prime is 28658687. The reversal of 28658681 is 18685682.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27206656 + 1452025 = 5216^2 + 1205^2 .

It is a cyclic number.

It is not a de Polignac number, because 28658681 - 2² = 28658677 is a prime.

It is a super-2 number, since 2×28658681² = 1642639993319522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (28658687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14329340 + 14329341.

It is an arithmetic number, because the mean of its divisors is an integer number (14329341).

Almost surely, 2^28658681 is an apocalyptic number.

It is an amenable number.

28658681 is a deficient number, since it is larger than the sum of its proper divisors (1).

28658681 is an equidigital number, since it uses as much as digits as its factorization.

28658681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 184320, while the sum is 44.

The square root of 28658681 is about 5353.3803339572. The cubic root of 28658681 is about 306.0215891755.

The spelling of 28658681 in words is "twenty-eight million, six hundred fifty-eight thousand, six hundred eighty-one".