28406247 has 4 divisors (see below), whose sum is σ = 37875000. Its totient is φ = 18937496.

The previous prime is 28406239. The next prime is 28406249. The reversal of 28406247 is 74260482.

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

It is a cyclic number.

It is not a de Polignac number, because 28406247 - 2³ = 28406239 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28406249) 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, 4734372 + ... + 4734377.

It is an arithmetic number, because the mean of its divisors is an integer number (9468750).

Almost surely, 2^28406247 is an apocalyptic number.

28406247 is a deficient number, since it is larger than the sum of its proper divisors (9468753).

28406247 is an equidigital number, since it uses as much as digits as its factorization.

28406247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9468752.

The product of its (nonzero) digits is 21504, while the sum is 33.

The square root of 28406247 is about 5329.7511198929. The cubic root of 28406247 is about 305.1204290168.

The spelling of 28406247 in words is "twenty-eight million, four hundred six thousand, two hundred forty-seven".