28098931 has 4 divisors (see below), whose sum is σ = 32113072. Its totient is φ = 24084792.

The previous prime is 28098887. The next prime is 28098937. The reversal of 28098931 is 13989082.

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

It is a cyclic number.

It is not a de Polignac number, because 28098931 - 2¹⁵ = 28066163 is a prime.

It is a super-2 number, since 2×28098931² = 1579099846685522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28098937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2007060 + ... + 2007073.

It is an arithmetic number, because the mean of its divisors is an integer number (8028268).

Almost surely, 2^28098931 is an apocalyptic number.

28098931 is a deficient number, since it is larger than the sum of its proper divisors (4014141).

28098931 is an equidigital number, since it uses as much as digits as its factorization.

28098931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4014140.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 28098931 is about 5300.8424802101. The cubic root of 28098931 is about 304.0161110748.

The spelling of 28098931 in words is "twenty-eight million, ninety-eight thousand, nine hundred thirty-one".