28738939 has 2 divisors, whose sum is σ = 28738940. Its totient is φ = 28738938.

The previous prime is 28738889. The next prime is 28738961. The reversal of 28738939 is 93983782.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28738939 - 2¹¹ = 28736891 is a prime.

It is a super-2 number, since 2×28738939² = 1651853229691442, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28738892 and 28738901.

It is not a weakly prime, because it can be changed into another prime (28738139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14369469 + 14369470.

It is an arithmetic number, because the mean of its divisors is an integer number (14369470).

Almost surely, 2^28738939 is an apocalyptic number.

28738939 is a deficient number, since it is larger than the sum of its proper divisors (1).

28738939 is an equidigital number, since it uses as much as digits as its factorization.

28738939 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 653184, while the sum is 49.

The square root of 28738939 is about 5360.8711045874. The cubic root of 28738939 is about 306.3069918091.

The spelling of 28738939 in words is "twenty-eight million, seven hundred thirty-eight thousand, nine hundred thirty-nine".