28991801 has 2 divisors, whose sum is σ = 28991802. Its totient is φ = 28991800.

The previous prime is 28991791. The next prime is 28991813. The reversal of 28991801 is 10819982.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27836176 + 1155625 = 5276^2 + 1075^2 .

It is a cyclic number.

It is not a de Polignac number, because 28991801 - 2⁶ = 28991737 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28991861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14495900 + 14495901.

It is an arithmetic number, because the mean of its divisors is an integer number (14495901).

Almost surely, 2^28991801 is an apocalyptic number.

It is an amenable number.

28991801 is a deficient number, since it is larger than the sum of its proper divisors (1).

28991801 is an equidigital number, since it uses as much as digits as its factorization.

28991801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 38.

The square root of 28991801 is about 5384.4034952815. The cubic root of 28991801 is about 307.2027259020.

It can be divided in two parts, 28991 and 801, that added together give a palindrome (29792).

The spelling of 28991801 in words is "twenty-eight million, nine hundred ninety-one thousand, eight hundred one".