28365521 has 2 divisors, whose sum is σ = 28365522. Its totient is φ = 28365520.

The previous prime is 28365517. The next prime is 28365523. The reversal of 28365521 is 12556382.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19891600 + 8473921 = 4460^2 + 2911^2 .

It is a cyclic number.

It is not a de Polignac number, because 28365521 - 2² = 28365517 is a prime.

Together with 28365523, 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 (28365523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14182760 + 14182761.

It is an arithmetic number, because the mean of its divisors is an integer number (14182761).

Almost surely, 2^28365521 is an apocalyptic number.

It is an amenable number.

28365521 is a deficient number, since it is larger than the sum of its proper divisors (1).

28365521 is an equidigital number, since it uses as much as digits as its factorization.

28365521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14400, while the sum is 32.

The square root of 28365521 is about 5325.9291208201. The cubic root of 28365521 is about 304.9745423525.

The spelling of 28365521 in words is "twenty-eight million, three hundred sixty-five thousand, five hundred twenty-one".