28220580 has 36 divisors (see below), whose sum is σ = 85602972. Its totient is φ = 7525440.

The previous prime is 28220579. The next prime is 28220597. The reversal of 28220580 is 8502282.

28220580 is a `hidden beast` number, since 2 + 82 + 2 + 0 + 580 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 12916836 + 15303744 = 3594^2 + 3912^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×28220580² = 1592802271072800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 78211 + ... + 78570.

Almost surely, 2^28220580 is an apocalyptic number.

28220580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28220580 is an abundant number, since it is smaller than the sum of its proper divisors (57382392).

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

28220580 is a wasteful number, since it uses less digits than its factorization.

28220580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156796 (or 156791 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 27.

The square root of 28220580 is about 5312.3045846412. The cubic root of 28220580 is about 304.4542061898.

The spelling of 28220580 in words is "twenty-eight million, two hundred twenty thousand, five hundred eighty".