28634405 has 4 divisors (see below), whose sum is σ = 34361292. Its totient is φ = 22907520.

The previous prime is 28634401. The next prime is 28634407. The reversal of 28634405 is 50443682.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50443682 = 2 ⋅25221841.

It can be written as a sum of positive squares in 2 ways, for example, as 21921124 + 6713281 = 4682^2 + 2591^2 .

It is not a de Polignac number, because 28634405 - 2² = 28634401 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 (28634401) 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, 2863436 + ... + 2863445.

It is an arithmetic number, because the mean of its divisors is an integer number (8590323).

Almost surely, 2^28634405 is an apocalyptic number.

It is an amenable number.

28634405 is a deficient number, since it is larger than the sum of its proper divisors (5726887).

28634405 is an equidigital number, since it uses as much as digits as its factorization.

28634405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5726886.

The product of its (nonzero) digits is 23040, while the sum is 32.

The square root of 28634405 is about 5351.1125011534. The cubic root of 28634405 is about 305.9351572061.

The spelling of 28634405 in words is "twenty-eight million, six hundred thirty-four thousand, four hundred five".