28747581 has 4 divisors (see below), whose sum is σ = 38330112. Its totient is φ = 19165052.

The previous prime is 28747577. The next prime is 28747651. The reversal of 28747581 is 18574782.

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 not a de Polignac number, because 28747581 - 2² = 28747577 is a prime.

It is a super-2 number, since 2×28747581² = 1652846826703122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28747501) 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, 4791261 + ... + 4791266.

It is an arithmetic number, because the mean of its divisors is an integer number (9582528).

Almost surely, 2^28747581 is an apocalyptic number.

It is an amenable number.

28747581 is a deficient number, since it is larger than the sum of its proper divisors (9582531).

28747581 is an equidigital number, since it uses as much as digits as its factorization.

28747581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9582530.

The product of its digits is 125440, while the sum is 42.

The square root of 28747581 is about 5361.6770697236. The cubic root of 28747581 is about 306.3376916171.

The spelling of 28747581 in words is "twenty-eight million, seven hundred forty-seven thousand, five hundred eighty-one".