28275991 has 2 divisors, whose sum is σ = 28275992. Its totient is φ = 28275990.

The previous prime is 28275979. The next prime is 28275997. The reversal of 28275991 is 19957282.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28275991 - 2⁹ = 28275479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28275997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14137995 + 14137996.

It is an arithmetic number, because the mean of its divisors is an integer number (14137996).

Almost surely, 2^28275991 is an apocalyptic number.

28275991 is a deficient number, since it is larger than the sum of its proper divisors (1).

28275991 is an equidigital number, since it uses as much as digits as its factorization.

28275991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 43.

The square root of 28275991 is about 5317.5173718569. The cubic root of 28275991 is about 304.6533407999.

The spelling of 28275991 in words is "twenty-eight million, two hundred seventy-five thousand, nine hundred ninety-one".