28391995349 has 4 divisors (see below), whose sum is σ = 28395618636. Its totient is φ = 28388372064.

The previous prime is 28391995343. The next prime is 28391995391. The reversal of 28391995349 is 94359919382.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 94359919382 = 2 ⋅47179959691.

It can be written as a sum of positive squares in 2 ways, for example, as 2222462449 + 26169532900 = 47143^2 + 161770^2 .

It is a cyclic number.

It is not a de Polignac number, because 28391995349 - 2²⁴ = 28375218133 is a prime.

It is a super-2 number, since 2×28391995349² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28391995291 and 28391995300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28391995343) 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, 1799864 + ... + 1815569.

It is an arithmetic number, because the mean of its divisors is an integer number (7098904659).

Almost surely, 2^28391995349 is an apocalyptic number.

It is an amenable number.

28391995349 is a deficient number, since it is larger than the sum of its proper divisors (3623287).

28391995349 is an equidigital number, since it uses as much as digits as its factorization.

28391995349 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3623286.

The product of its digits is 18895680, while the sum is 62.

The spelling of 28391995349 in words is "twenty-eight billion, three hundred ninety-one million, nine hundred ninety-five thousand, three hundred forty-nine".