28973440 has 64 divisors (see below), whose sum is σ = 73366560. Its totient is φ = 10903552.

The previous prime is 28973411. The next prime is 28973489. The reversal of 28973440 is 4437982.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is a self number, because there is not a number n which added to its sum of digits gives 28973440.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9549 + ... + 12211.

Almost surely, 2^28973440 is an apocalyptic number.

28973440 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 28973440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36683280).

28973440 is an abundant number, since it is smaller than the sum of its proper divisors (44393120).

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

28973440 is a wasteful number, since it uses less digits than its factorization.

28973440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2699 (or 2687 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 37.

The square root of 28973440 is about 5382.6982081480. The cubic root of 28973440 is about 307.1378599718.

The spelling of 28973440 in words is "twenty-eight million, nine hundred seventy-three thousand, four hundred forty".