28820931 has 8 divisors (see below), whose sum is σ = 38824464. Its totient is φ = 19015680.

The previous prime is 28820927. The next prime is 28820941. The reversal of 28820931 is 13902882.

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

It is not a de Polignac number, because 28820931 - 2² = 28820927 is a prime.

It is a super-4 number, since 4×28820931⁴ (a number of 31 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 28820892 and 28820901.

It is not an unprimeable number, because it can be changed into a prime (28820941) 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, 49230 + ... + 49811.

It is an arithmetic number, because the mean of its divisors is an integer number (4853058).

Almost surely, 2^28820931 is an apocalyptic number.

28820931 is a deficient number, since it is larger than the sum of its proper divisors (10003533).

28820931 is an equidigital number, since it uses as much as digits as its factorization.

28820931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99141.

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

The square root of 28820931 is about 5368.5129225885. The cubic root of 28820931 is about 306.5980124879.

The spelling of 28820931 in words is "twenty-eight million, eight hundred twenty thousand, nine hundred thirty-one".