28815401 has 4 divisors (see below), whose sum is σ = 29100804. Its totient is φ = 28530000.

The previous prime is 28815379. The next prime is 28815403. The reversal of 28815401 is 10451882.

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 23775376 + 5040025 = 4876^2 + 2245^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28815401 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28815403) 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, 142550 + ... + 142751.

It is an arithmetic number, because the mean of its divisors is an integer number (7275201).

Almost surely, 2^28815401 is an apocalyptic number.

It is an amenable number.

28815401 is a deficient number, since it is larger than the sum of its proper divisors (285403).

28815401 is a wasteful number, since it uses less digits than its factorization.

28815401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285402.

The product of its (nonzero) digits is 2560, while the sum is 29.

The square root of 28815401 is about 5367.9978576747. The cubic root of 28815401 is about 306.5784017929.

The spelling of 28815401 in words is "twenty-eight million, eight hundred fifteen thousand, four hundred one".