28163730 has 160 divisors (see below), whose sum is σ = 87122304. Its totient is φ = 5795328.

The previous prime is 28163699. The next prime is 28163731. The reversal of 28163730 is 3736182.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (28163731) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1224499 + ... + 1224521.

Almost surely, 2^28163730 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28163730, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43561152).

28163730 is an abundant number, since it is smaller than the sum of its proper divisors (58958574).

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

28163730 is a wasteful number, since it uses less digits than its factorization.

28163730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78 (or 57 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 28163730 is about 5306.9511020924. The cubic root of 28163730 is about 304.2496290450.

The spelling of 28163730 in words is "twenty-eight million, one hundred sixty-three thousand, seven hundred thirty".