28840247 has 8 divisors (see below), whose sum is σ = 29257680. Its totient is φ = 28425600.

The previous prime is 28840243. The next prime is 28840249. The reversal of 28840247 is 74204882.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28840247 - 2² = 28840243 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28840241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28079 + ... + 29087.

It is an arithmetic number, because the mean of its divisors is an integer number (3657210).

Almost surely, 2^28840247 is an apocalyptic number.

28840247 is a deficient number, since it is larger than the sum of its proper divisors (417433).

28840247 is a wasteful number, since it uses less digits than its factorization.

28840247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1393.

The product of its (nonzero) digits is 28672, while the sum is 35.

The square root of 28840247 is about 5370.3116296915. The cubic root of 28840247 is about 306.6664919396. Note that the first 3 decimals are identical.

The spelling of 28840247 in words is "twenty-eight million, eight hundred forty thousand, two hundred forty-seven".