28078639 has 2 divisors, whose sum is σ = 28078640. Its totient is φ = 28078638.

The previous prime is 28078627. The next prime is 28078649. The reversal of 28078639 is 93687082.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28078639 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28078595 and 28078604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28078649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14039319 + 14039320.

It is an arithmetic number, because the mean of its divisors is an integer number (14039320).

Almost surely, 2^28078639 is an apocalyptic number.

28078639 is a deficient number, since it is larger than the sum of its proper divisors (1).

28078639 is an equidigital number, since it uses as much as digits as its factorization.

28078639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145152, while the sum is 43.

The square root of 28078639 is about 5298.9280991536. The cubic root of 28078639 is about 303.9429104187.

The spelling of 28078639 in words is "twenty-eight million, seventy-eight thousand, six hundred thirty-nine".