28301681 has 2 divisors, whose sum is σ = 28301682. Its totient is φ = 28301680.

The previous prime is 28301677. The next prime is 28301683. The reversal of 28301681 is 18610382.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25411681 + 2890000 = 5041^2 + 1700^2 .

It is a cyclic number.

It is not a de Polignac number, because 28301681 - 2² = 28301677 is a prime.

It is a super-2 number, since 2×28301681² = 1601970294851522, which contains 22 as substring.

Together with 28301683, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28301683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14150840 + 14150841.

It is an arithmetic number, because the mean of its divisors is an integer number (14150841).

Almost surely, 2^28301681 is an apocalyptic number.

It is an amenable number.

28301681 is a deficient number, since it is larger than the sum of its proper divisors (1).

28301681 is an equidigital number, since it uses as much as digits as its factorization.

28301681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 28301681 is about 5319.9324243829. The cubic root of 28301681 is about 304.7455765918.

It can be divided in two parts, 28301 and 681, that added together give a palindrome (28982).

The spelling of 28301681 in words is "twenty-eight million, three hundred one thousand, six hundred eighty-one".