28251401 has 2 divisors, whose sum is σ = 28251402. Its totient is φ = 28251400.

The previous prime is 28251389. The next prime is 28251403. The reversal of 28251401 is 10415282.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26988025 + 1263376 = 5195^2 + 1124^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28251401 is a prime.

Together with 28251403, 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 (28251403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14125700 + 14125701.

It is an arithmetic number, because the mean of its divisors is an integer number (14125701).

Almost surely, 2^28251401 is an apocalyptic number.

It is an amenable number.

28251401 is a deficient number, since it is larger than the sum of its proper divisors (1).

28251401 is an equidigital number, since it uses as much as digits as its factorization.

28251401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 640, while the sum is 23.

The square root of 28251401 is about 5315.2046997270. The cubic root of 28251401 is about 304.5650020355.

Adding to 28251401 its reverse (10415282), we get a palindrome (38666683).

The spelling of 28251401 in words is "twenty-eight million, two hundred fifty-one thousand, four hundred one".