28928031 has 8 divisors (see below), whose sum is σ = 42077184. Its totient is φ = 17532120.

The previous prime is 28928023. The next prime is 28928047. The reversal of 28928031 is 13082982.

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

It is not a de Polignac number, because 28928031 - 2³ = 28928023 is a prime.

It is a super-2 number, since 2×28928031² = 1673661955073922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 876607 = 28928031 / (2 + 8 + 9 + 2 + 8 + 0 + 3 + 1).

It is a junction number, because it is equal to n+sod(n) for n = 28927983 and 28928001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28928021) 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, 438271 + ... + 438336.

It is an arithmetic number, because the mean of its divisors is an integer number (5259648).

Almost surely, 2^28928031 is an apocalyptic number.

28928031 is a deficient number, since it is larger than the sum of its proper divisors (13149153).

28928031 is a wasteful number, since it uses less digits than its factorization.

28928031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 876621.

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 28928031 is about 5378.4785023276. The cubic root of 28928031 is about 306.9773208073.

The spelling of 28928031 in words is "twenty-eight million, nine hundred twenty-eight thousand, thirty-one".