28755581 has 2 divisors, whose sum is σ = 28755582. Its totient is φ = 28755580.

The previous prime is 28755547. The next prime is 28755613. The reversal of 28755581 is 18555782.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15132100 + 13623481 = 3890^2 + 3691^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28755581 is a prime.

It is a super-2 number, since 2×28755581² = 1653766877295122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28755511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14377790 + 14377791.

It is an arithmetic number, because the mean of its divisors is an integer number (14377791).

Almost surely, 2^28755581 is an apocalyptic number.

It is an amenable number.

28755581 is a deficient number, since it is larger than the sum of its proper divisors (1).

28755581 is an equidigital number, since it uses as much as digits as its factorization.

28755581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 112000, while the sum is 41.

The square root of 28755581 is about 5362.4230530610. The cubic root of 28755581 is about 306.3661053033.

The spelling of 28755581 in words is "twenty-eight million, seven hundred fifty-five thousand, five hundred eighty-one".