28913639 has 2 divisors, whose sum is σ = 28913640. Its totient is φ = 28913638.

The previous prime is 28913627. The next prime is 28913657. The reversal of 28913639 is 93631982.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28913639 - 2⁴ = 28913623 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 28913596 and 28913605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28913239) 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, 14456819 + 14456820.

It is an arithmetic number, because the mean of its divisors is an integer number (14456820).

Almost surely, 2^28913639 is an apocalyptic number.

28913639 is a deficient number, since it is larger than the sum of its proper divisors (1).

28913639 is an equidigital number, since it uses as much as digits as its factorization.

28913639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69984, while the sum is 41.

The square root of 28913639 is about 5377.1404110363. The cubic root of 28913639 is about 306.9264042128.

The spelling of 28913639 in words is "twenty-eight million, nine hundred thirteen thousand, six hundred thirty-nine".