28411391 has 4 divisors (see below), whose sum is σ = 28893000. Its totient is φ = 27929784.

The previous prime is 28411351. The next prime is 28411399. The reversal of 28411391 is 19311482.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19311482 = 2 ⋅9655741.

It is a cyclic number.

It is not a de Polignac number, because 28411391 - 2²² = 24217087 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28411399) 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, 240716 + ... + 240833.

It is an arithmetic number, because the mean of its divisors is an integer number (7223250).

Almost surely, 2^28411391 is an apocalyptic number.

28411391 is a deficient number, since it is larger than the sum of its proper divisors (481609).

28411391 is an equidigital number, since it uses as much as digits as its factorization.

28411391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481608.

The product of its digits is 1728, while the sum is 29.

The square root of 28411391 is about 5330.2336721761. The cubic root of 28411391 is about 305.1388456789.

Subtracting from 28411391 its reverse (19311482), we obtain a palindrome (9099909).

The spelling of 28411391 in words is "twenty-eight million, four hundred eleven thousand, three hundred ninety-one".