28931478 has 8 divisors (see below), whose sum is σ = 57862968. Its totient is φ = 9643824.

The previous prime is 28931477. The next prime is 28931491. The reversal of 28931478 is 87413982.

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

28931478 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28931477) 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, 2410951 + ... + 2410962.

It is an arithmetic number, because the mean of its divisors is an integer number (7232871).

Almost surely, 2^28931478 is an apocalyptic number.

28931478 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28931478 is a wasteful number, since it uses less digits than its factorization.

28931478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4821918.

The product of its digits is 96768, while the sum is 42.

The square root of 28931478 is about 5378.7989365657. The cubic root of 28931478 is about 306.9895132352.

It can be divided in two parts, 2893 and 1478, that added together give a triangular number (4371 = T₉₃).

The spelling of 28931478 in words is "twenty-eight million, nine hundred thirty-one thousand, four hundred seventy-eight".