28750681 has 4 divisors (see below), whose sum is σ = 28761552. Its totient is φ = 28739812.

The previous prime is 28750679. The next prime is 28750727. The reversal of 28750681 is 18605782.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 28750681 - 2¹ = 28750679 is a prime.

It is a super-2 number, since 2×28750681² = 1653203315927522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28750681.

It is not an unprimeable number, because it can be changed into a prime (28750651) 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, 1386 + ... + 7708.

It is an arithmetic number, because the mean of its divisors is an integer number (7190388).

Almost surely, 2^28750681 is an apocalyptic number.

It is an amenable number.

28750681 is a deficient number, since it is larger than the sum of its proper divisors (10871).

28750681 is an equidigital number, since it uses as much as digits as its factorization.

28750681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10870.

The product of its (nonzero) digits is 26880, while the sum is 37.

The square root of 28750681 is about 5361.9661505832. The cubic root of 28750681 is about 306.3487025460.

The spelling of 28750681 in words is "twenty-eight million, seven hundred fifty thousand, six hundred eighty-one".