28505011 has 2 divisors, whose sum is σ = 28505012. Its totient is φ = 28505010.

The previous prime is 28505003. The next prime is 28505021. The reversal of 28505011 is 11050582.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28505011 - 2³ = 28505003 is a prime.

It is a super-2 number, since 2×28505011² = 1625071304220242, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28505021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14252505 + 14252506.

It is an arithmetic number, because the mean of its divisors is an integer number (14252506).

Almost surely, 2^28505011 is an apocalyptic number.

28505011 is a deficient number, since it is larger than the sum of its proper divisors (1).

28505011 is an equidigital number, since it uses as much as digits as its factorization.

28505011 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 400, while the sum is 22.

The square root of 28505011 is about 5339.0084285380. The cubic root of 28505011 is about 305.4736383724.

Adding to 28505011 its reverse (11050582), we get a palindrome (39555593).

The spelling of 28505011 in words is "twenty-eight million, five hundred five thousand, eleven".