28702290 has 64 divisors (see below), whose sum is σ = 73592064. Its totient is φ = 7139328.

The previous prime is 28702279. The next prime is 28702291. The reversal of 28702290 is 9220782.

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 (28702291) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 85002 + ... + 85338.

It is an arithmetic number, because the mean of its divisors is an integer number (1149876).

Almost surely, 2^28702290 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28702290, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36796032).

28702290 is an abundant number, since it is smaller than the sum of its proper divisors (44889774).

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

28702290 is a wasteful number, since it uses less digits than its factorization.

28702290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 531.

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 28702290 is about 5357.4518196620. The cubic root of 28702290 is about 306.1767316047.

The spelling of 28702290 in words is "twenty-eight million, seven hundred two thousand, two hundred ninety".