28156247 has 8 divisors (see below), whose sum is σ = 32211456. Its totient is φ = 24109272.

The previous prime is 28156241. The next prime is 28156259. The reversal of 28156247 is 74265182.

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 28156247 - 2⁴ = 28156231 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 (28156241) 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, 9998 + ... + 12500.

It is an arithmetic number, because the mean of its divisors is an integer number (4026432).

Almost surely, 2^28156247 is an apocalyptic number.

28156247 is a deficient number, since it is larger than the sum of its proper divisors (4055209).

28156247 is a wasteful number, since it uses less digits than its factorization.

28156247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4117.

The product of its digits is 26880, while the sum is 35.

The square root of 28156247 is about 5306.2460365121. The cubic root of 28156247 is about 304.2226806538. Note that the first 3 decimals are identical.

The spelling of 28156247 in words is "twenty-eight million, one hundred fifty-six thousand, two hundred forty-seven".