28252921 has 2 divisors, whose sum is σ = 28252922. Its totient is φ = 28252920.

The previous prime is 28252919. The next prime is 28252927. The reversal of 28252921 is 12925282.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27415696 + 837225 = 5236^2 + 915^2 .

It is a cyclic number.

It is not a de Polignac number, because 28252921 - 2¹ = 28252919 is a prime.

Together with 28252919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (28252927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14126460 + 14126461.

It is an arithmetic number, because the mean of its divisors is an integer number (14126461).

Almost surely, 2^28252921 is an apocalyptic number.

It is an amenable number.

28252921 is a deficient number, since it is larger than the sum of its proper divisors (1).

28252921 is an equidigital number, since it uses as much as digits as its factorization.

28252921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5760, while the sum is 31.

The square root of 28252921 is about 5315.3476838303. The cubic root of 28252921 is about 304.5704640714.

The spelling of 28252921 in words is "twenty-eight million, two hundred fifty-two thousand, nine hundred twenty-one".