28220670 has 64 divisors (see below), whose sum is σ = 75939840. Its totient is φ = 7457184.

The previous prime is 28220659. The next prime is 28220671. The reversal of 28220670 is 7602282.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28220671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 33879 + ... + 34701.

It is an arithmetic number, because the mean of its divisors is an integer number (1186560).

Almost surely, 2^28220670 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28220670, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37969920).

28220670 is an abundant number, since it is smaller than the sum of its proper divisors (47719170).

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

28220670 is a wasteful number, since it uses less digits than its factorization.

28220670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 966 (or 960 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 28220670 is about 5312.3130555343. The cubic root of 28220670 is about 304.4545298408.

The spelling of 28220670 in words is "twenty-eight million, two hundred twenty thousand, six hundred seventy".