28402447 has 4 divisors (see below), whose sum is σ = 29637360. Its totient is φ = 27167536.

The previous prime is 28402433. The next prime is 28402453. The reversal of 28402447 is 74420482.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28402447 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 (28402487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 617422 + ... + 617467.

It is an arithmetic number, because the mean of its divisors is an integer number (7409340).

Almost surely, 2^28402447 is an apocalyptic number.

28402447 is a deficient number, since it is larger than the sum of its proper divisors (1234913).

28402447 is a wasteful number, since it uses less digits than its factorization.

28402447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1234912.

The product of its (nonzero) digits is 14336, while the sum is 31.

The square root of 28402447 is about 5329.3946185284. The cubic root of 28402447 is about 305.1068227452.

The spelling of 28402447 in words is "twenty-eight million, four hundred two thousand, four hundred forty-seven".