28947839 has 2 divisors, whose sum is σ = 28947840. Its totient is φ = 28947838.

The previous prime is 28947803. The next prime is 28947857. The reversal of 28947839 is 93874982.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28947839 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28947739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14473919 + 14473920.

It is an arithmetic number, because the mean of its divisors is an integer number (14473920).

Almost surely, 2^28947839 is an apocalyptic number.

28947839 is a deficient number, since it is larger than the sum of its proper divisors (1).

28947839 is an equidigital number, since it uses as much as digits as its factorization.

28947839 is an evil number, because the sum of its binary digits is even.

The product of its digits is 870912, while the sum is 50.

The square root of 28947839 is about 5380.3196001725. The cubic root of 28947839 is about 307.0473707349.

The spelling of 28947839 in words is "twenty-eight million, nine hundred forty-seven thousand, eight hundred thirty-nine".