28758131 has 4 divisors (see below), whose sum is σ = 29152152. Its totient is φ = 28364112.

The previous prime is 28758113. The next prime is 28758137. The reversal of 28758131 is 13185782.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13185782 = 2 ⋅6592891.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28758131 is a prime.

It is a super-2 number, since 2×28758131² = 1654060197226322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28758091 and 28758100.

It is not an unprimeable number, because it can be changed into a prime (28758137) 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, 196901 + ... + 197046.

It is an arithmetic number, because the mean of its divisors is an integer number (7288038).

Almost surely, 2^28758131 is an apocalyptic number.

28758131 is a deficient number, since it is larger than the sum of its proper divisors (394021).

28758131 is an equidigital number, since it uses as much as digits as its factorization.

28758131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394020.

The product of its digits is 13440, while the sum is 35.

The square root of 28758131 is about 5362.6608134395. The cubic root of 28758131 is about 306.3751610582.

The spelling of 28758131 in words is "twenty-eight million, seven hundred fifty-eight thousand, one hundred thirty-one".