28781567 has 2 divisors, whose sum is σ = 28781568. Its totient is φ = 28781566.

The previous prime is 28781563. The next prime is 28781573. The reversal of 28781567 is 76518782.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28781567 - 2² = 28781563 is a prime.

It is a super-3 number, since 3×28781567³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28781563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14390783 + 14390784.

It is an arithmetic number, because the mean of its divisors is an integer number (14390784).

Almost surely, 2^28781567 is an apocalyptic number.

28781567 is a deficient number, since it is larger than the sum of its proper divisors (1).

28781567 is an equidigital number, since it uses as much as digits as its factorization.

28781567 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 188160, while the sum is 44.

The square root of 28781567 is about 5364.8454777375. The cubic root of 28781567 is about 306.4583637147.

The spelling of 28781567 in words is "twenty-eight million, seven hundred eighty-one thousand, five hundred sixty-seven".