28931420 has 48 divisors (see below), whose sum is σ = 69854400. Its totient is φ = 9859584.

The previous prime is 28931411. The next prime is 28931423. The reversal of 28931420 is 2413982.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28931423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27056 + ... + 28104.

It is an arithmetic number, because the mean of its divisors is an integer number (1455300).

Almost surely, 2^28931420 is an apocalyptic number.

28931420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28931420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34927200).

28931420 is an abundant number, since it is smaller than the sum of its proper divisors (40922980).

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

28931420 is a wasteful number, since it uses less digits than its factorization.

28931420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1262 (or 1260 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 28931420 is about 5378.7935450248. The cubic root of 28931420 is about 306.9893080907.

The spelling of 28931420 in words is "twenty-eight million, nine hundred thirty-one thousand, four hundred twenty".