28239487 has 2 divisors, whose sum is σ = 28239488. Its totient is φ = 28239486.

The previous prime is 28239467. The next prime is 28239509. The reversal of 28239487 is 78493282.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28239487 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28239427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14119743 + 14119744.

It is an arithmetic number, because the mean of its divisors is an integer number (14119744).

Almost surely, 2^28239487 is an apocalyptic number.

28239487 is a deficient number, since it is larger than the sum of its proper divisors (1).

28239487 is an equidigital number, since it uses as much as digits as its factorization.

28239487 is an evil number, because the sum of its binary digits is even.

The product of its digits is 193536, while the sum is 43.

The square root of 28239487 is about 5314.0838344911. The cubic root of 28239487 is about 304.5221829481.

The spelling of 28239487 in words is "twenty-eight million, two hundred thirty-nine thousand, four hundred eighty-seven".