28058981 has 4 divisors (see below), whose sum is σ = 28106892. Its totient is φ = 28011072.

The previous prime is 28058977. The next prime is 28059001. The reversal of 28058981 is 18985082.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21252100 + 6806881 = 4610^2 + 2609^2 .

It is a cyclic number.

It is not a de Polignac number, because 28058981 - 2² = 28058977 is a prime.

It is a super-2 number, since 2×28058981² = 1574612829516722, 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 (28058081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23066 + ... + 24251.

It is an arithmetic number, because the mean of its divisors is an integer number (7026723).

Almost surely, 2^28058981 is an apocalyptic number.

It is an amenable number.

28058981 is a deficient number, since it is larger than the sum of its proper divisors (47911).

28058981 is an equidigital number, since it uses as much as digits as its factorization.

28058981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47910.

The product of its (nonzero) digits is 46080, while the sum is 41.

The square root of 28058981 is about 5297.0728709354. The cubic root of 28058981 is about 303.8719631929.

The spelling of 28058981 in words is "twenty-eight million, fifty-eight thousand, nine hundred eighty-one".