28567381 has 2 divisors, whose sum is σ = 28567382.
Its totient is φ = 28567380.
The previous prime is 28567321. The next prime is 28567391. The reversal of 28567381 is 18376582.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 24344356 + 4223025 = 4934^2 + 2055^2
It is a cyclic number.
It is not a de Polignac number, because 28567381 - 213 = 28559189 is a prime.
It is a super-2 number, since 2×285673812 = 1632190514398322, which contains 22 as substring.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (28567321) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14283690 + 14283691.
It is an arithmetic number, because the mean of its divisors is an integer number (14283691).
Almost surely, 228567381 is an apocalyptic number.
It is an amenable number.
28567381 is a deficient number, since it is larger than the sum of its proper divisors (1).
28567381 is an equidigital number, since it uses as much as digits as its factorization.
28567381 is an evil number, because the sum of its binary digits is even.
The product of its digits is 80640, while the sum is 40.
The square root of 28567381 is about 5344.8462092000.
The cubic root of 28567381 is about 305.6962718819.
The spelling of 28567381 in words is "twenty-eight million, five hundred sixty-seven thousand, three hundred eighty-one".