28995581 has 4 divisors (see below), whose sum is σ = 29173632. Its totient is φ = 28817532.

The previous prime is 28995559. The next prime is 28995583. The reversal of 28995581 is 18559982.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28995581 is a prime.

It is a super-2 number, since 2×28995581² = 1681487435055122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28995583) 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 in 3 ways as a sum of consecutive naturals, for example, 88781 + ... + 89106.

It is an arithmetic number, because the mean of its divisors is an integer number (7293408).

Almost surely, 2^28995581 is an apocalyptic number.

It is an amenable number.

28995581 is a deficient number, since it is larger than the sum of its proper divisors (178051).

28995581 is a wasteful number, since it uses less digits than its factorization.

28995581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178050.

The product of its digits is 259200, while the sum is 47.

The square root of 28995581 is about 5384.7544976535. The cubic root of 28995581 is about 307.2160765252.

The spelling of 28995581 in words is "twenty-eight million, nine hundred ninety-five thousand, five hundred eighty-one".