28616639 has 2 divisors, whose sum is σ = 28616640. Its totient is φ = 28616638.

The previous prime is 28616617. The next prime is 28616663. The reversal of 28616639 is 93661682.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28616639 - 2¹² = 28612543 is a prime.

It is a Sophie Germain prime.

It is equal to p_1777397 and since 28616639 and 1777397 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 28616596 and 28616605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28606639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14308319 + 14308320.

It is an arithmetic number, because the mean of its divisors is an integer number (14308320).

Almost surely, 2^28616639 is an apocalyptic number.

28616639 is a deficient number, since it is larger than the sum of its proper divisors (1).

28616639 is an equidigital number, since it uses as much as digits as its factorization.

28616639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 93312, while the sum is 41.

The square root of 28616639 is about 5349.4522149469. The cubic root of 28616639 is about 305.8718723980.

The spelling of 28616639 in words is "twenty-eight million, six hundred sixteen thousand, six hundred thirty-nine".