28409477 has 4 divisors (see below), whose sum is σ = 28427916. Its totient is φ = 28391040.

The previous prime is 28409471. The next prime is 28409497. The reversal of 28409477 is 77490482.

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

It can be written as a sum of positive squares in 2 ways, for example, as 27552001 + 857476 = 5249^2 + 926^2 .

It is a cyclic number.

It is not a de Polignac number, because 28409477 - 2⁸ = 28409221 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 (28409471) 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, 6674 + ... + 10067.

It is an arithmetic number, because the mean of its divisors is an integer number (7106979).

Almost surely, 2^28409477 is an apocalyptic number.

It is an amenable number.

28409477 is a deficient number, since it is larger than the sum of its proper divisors (18439).

28409477 is a wasteful number, since it uses less digits than its factorization.

28409477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18438.

The product of its (nonzero) digits is 112896, while the sum is 41.

The square root of 28409477 is about 5330.0541273049. The cubic root of 28409477 is about 305.1319933937.

The spelling of 28409477 in words is "twenty-eight million, four hundred nine thousand, four hundred seventy-seven".