28337681 has 2 divisors, whose sum is σ = 28337682. Its totient is φ = 28337680.

The previous prime is 28337629. The next prime is 28337719. The reversal of 28337681 is 18673382.

It is a happy number.

It is an a-pointer prime, because the next prime (28337719) can be obtained adding 28337681 to its sum of digits (38).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25806400 + 2531281 = 5080^2 + 1591^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28337681 is a prime.

It is a super-2 number, since 2×28337681² = 1606048328915522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28330681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14168840 + 14168841.

It is an arithmetic number, because the mean of its divisors is an integer number (14168841).

Almost surely, 2^28337681 is an apocalyptic number.

It is an amenable number.

28337681 is a deficient number, since it is larger than the sum of its proper divisors (1).

28337681 is an equidigital number, since it uses as much as digits as its factorization.

28337681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48384, while the sum is 38.

The square root of 28337681 is about 5323.3148507298. The cubic root of 28337681 is about 304.8747349078.

The spelling of 28337681 in words is "twenty-eight million, three hundred thirty-seven thousand, six hundred eighty-one".