28061213 has 2 divisors, whose sum is σ = 28061214. Its totient is φ = 28061212.

The previous prime is 28061191. The next prime is 28061239. The reversal of 28061213 is 31216082.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25381444 + 2679769 = 5038^2 + 1637^2 .

It is a cyclic number.

It is not a de Polignac number, because 28061213 - 2⁸ = 28060957 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28061263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14030606 + 14030607.

It is an arithmetic number, because the mean of its divisors is an integer number (14030607).

Almost surely, 2^28061213 is an apocalyptic number.

It is an amenable number.

28061213 is a deficient number, since it is larger than the sum of its proper divisors (1).

28061213 is an equidigital number, since it uses as much as digits as its factorization.

28061213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 28061213 is about 5297.2835491410. The cubic root of 28061213 is about 303.8800203189.

Adding to 28061213 its reverse (31216082), we get a palindrome (59277295).

The spelling of 28061213 in words is "twenty-eight million, sixty-one thousand, two hundred thirteen".