28031940 has 192 divisors, whose sum is σ = 94993920. Its totient is φ = 6842880.

The previous prime is 28031911. The next prime is 28031959. The reversal of 28031940 is 4913082.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 459510 + ... + 459570.

It is an arithmetic number, because the mean of its divisors is an integer number (494760).

Almost surely, 2^28031940 is an apocalyptic number.

28031940 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 28031940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47496960).

28031940 is an abundant number, since it is smaller than the sum of its proper divisors (66961980).

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

28031940 is a wasteful number, since it uses less digits than its factorization.

28031940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 28031940 is about 5294.5198082546. The cubic root of 28031940 is about 303.7743159927.

The spelling of 28031940 in words is "twenty-eight million, thirty-one thousand, nine hundred forty".