28047881 has 2 divisors, whose sum is σ = 28047882. Its totient is φ = 28047880.

The previous prime is 28047871. The next prime is 28047883. The reversal of 28047881 is 18874082.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24403600 + 3644281 = 4940^2 + 1909^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28047881 is a prime.

It is a super-2 number, since 2×28047881² = 1573367257180322, which contains 22 as substring.

Together with 28047883, 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 (28047883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14023940 + 14023941.

It is an arithmetic number, because the mean of its divisors is an integer number (14023941).

Almost surely, 2^28047881 is an apocalyptic number.

It is an amenable number.

28047881 is a deficient number, since it is larger than the sum of its proper divisors (1).

28047881 is an equidigital number, since it uses as much as digits as its factorization.

28047881 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28672, while the sum is 38.

The square root of 28047881 is about 5296.0250188231. The cubic root of 28047881 is about 303.8318878047.

The spelling of 28047881 in words is "twenty-eight million, forty-seven thousand, eight hundred eighty-one".