28903561 has 2 divisors, whose sum is σ = 28903562. Its totient is φ = 28903560.

The previous prime is 28903559. The next prime is 28903573. The reversal of 28903561 is 16530982.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17472400 + 11431161 = 4180^2 + 3381^2 .

It is a cyclic number.

It is not a de Polignac number, because 28903561 - 2¹ = 28903559 is a prime.

Together with 28903559, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (28903531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14451780 + 14451781.

It is an arithmetic number, because the mean of its divisors is an integer number (14451781).

Almost surely, 2^28903561 is an apocalyptic number.

It is an amenable number.

28903561 is a deficient number, since it is larger than the sum of its proper divisors (1).

28903561 is an equidigital number, since it uses as much as digits as its factorization.

28903561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 28903561 is about 5376.2032141652. The cubic root of 28903561 is about 306.8907398013.

The spelling of 28903561 in words is "twenty-eight million, nine hundred three thousand, five hundred sixty-one".