28593781 has 2 divisors, whose sum is σ = 28593782. Its totient is φ = 28593780.

The previous prime is 28593767. The next prime is 28593809. The reversal of 28593781 is 18739582.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27394756 + 1199025 = 5234^2 + 1095^2 .

It is a cyclic number.

It is not a de Polignac number, because 28593781 - 2¹³ = 28585589 is a prime.

It is a super-2 number, since 2×28593781² = 1635208623751922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28513781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14296890 + 14296891.

It is an arithmetic number, because the mean of its divisors is an integer number (14296891).

Almost surely, 2^28593781 is an apocalyptic number.

It is an amenable number.

28593781 is a deficient number, since it is larger than the sum of its proper divisors (1).

28593781 is an equidigital number, since it uses as much as digits as its factorization.

28593781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 43.

The square root of 28593781 is about 5347.3153077035. The cubic root of 28593781 is about 305.7904106811.

The spelling of 28593781 in words is "twenty-eight million, five hundred ninety-three thousand, seven hundred eighty-one".