28771439 has 2 divisors, whose sum is σ = 28771440. Its totient is φ = 28771438.

The previous prime is 28771373. The next prime is 28771447. The reversal of 28771439 is 93417782.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28771439 - 2²⁴ = 11994223 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 28771396 and 28771405.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28771489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14385719 + 14385720.

It is an arithmetic number, because the mean of its divisors is an integer number (14385720).

Almost surely, 2^28771439 is an apocalyptic number.

28771439 is a deficient number, since it is larger than the sum of its proper divisors (1).

28771439 is an equidigital number, since it uses as much as digits as its factorization.

28771439 is an evil number, because the sum of its binary digits is even.

The product of its digits is 84672, while the sum is 41.

The square root of 28771439 is about 5363.9014718766. The cubic root of 28771439 is about 306.4224127599.

It can be divided in two parts, 2877 and 1439, that multiplied together give a triangular number (4140003 = T₂₈₇₇).

The spelling of 28771439 in words is "twenty-eight million, seven hundred seventy-one thousand, four hundred thirty-nine".