28129901 has 2 divisors, whose sum is σ = 28129902. Its totient is φ = 28129900.

The previous prime is 28129891. The next prime is 28129921. The reversal of 28129901 is 10992182.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20484676 + 7645225 = 4526^2 + 2765^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28129901 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28129921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14064950 + 14064951.

It is an arithmetic number, because the mean of its divisors is an integer number (14064951).

Almost surely, 2^28129901 is an apocalyptic number.

It is an amenable number.

28129901 is a deficient number, since it is larger than the sum of its proper divisors (1).

28129901 is an equidigital number, since it uses as much as digits as its factorization.

28129901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 32.

The square root of 28129901 is about 5303.7629094823. The cubic root of 28129901 is about 304.1277632694.

The spelling of 28129901 in words is "twenty-eight million, one hundred twenty-nine thousand, nine hundred one".