28274157581 has 2 divisors, whose sum is σ = 28274157582. Its totient is φ = 28274157580.

The previous prime is 28274157557. The next prime is 28274157589. The reversal of 28274157581 is 18575147282.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21753595081 + 6520562500 = 147491^2 + 80750^2 .

It is a cyclic number.

It is not a de Polignac number, because 28274157581 - 2¹⁸ = 28273895437 is a prime.

It is a super-2 number, since 2×28274157581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28274157589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14137078790 + 14137078791.

It is an arithmetic number, because the mean of its divisors is an integer number (14137078791).

Almost surely, 2^28274157581 is an apocalyptic number.

It is an amenable number.

28274157581 is a deficient number, since it is larger than the sum of its proper divisors (1).

28274157581 is an equidigital number, since it uses as much as digits as its factorization.

28274157581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1254400, while the sum is 50.

The spelling of 28274157581 in words is "twenty-eight billion, two hundred seventy-four million, one hundred fifty-seven thousand, five hundred eighty-one".