28281601 has 2 divisors, whose sum is σ = 28281602. Its totient is φ = 28281600.

The previous prime is 28281599. The next prime is 28281623. The reversal of 28281601 is 10618282.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25959025 + 2322576 = 5095^2 + 1524^2 .

It is a cyclic number.

It is not a de Polignac number, because 28281601 - 2¹ = 28281599 is a prime.

Together with 28281599, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 28281601.

It is not a weakly prime, because it can be changed into another prime (28281691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14140800 + 14140801.

It is an arithmetic number, because the mean of its divisors is an integer number (14140801).

Almost surely, 2^28281601 is an apocalyptic number.

It is an amenable number.

28281601 is a deficient number, since it is larger than the sum of its proper divisors (1).

28281601 is an equidigital number, since it uses as much as digits as its factorization.

28281601 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 28281601 is about 5318.0448474980. The cubic root of 28281601 is about 304.6734873643.

Adding to 28281601 its reverse (10618282), we get a palindrome (38899883).

It can be divided in two parts, 28281 and 601, that added together give a palindrome (28882).

The spelling of 28281601 in words is "twenty-eight million, two hundred eighty-one thousand, six hundred one".