28620445221 has 24 divisors (see below), whose sum is σ = 42239957760. Its totient is φ = 18665608416.

The previous prime is 28620445201. The next prime is 28620445223. The reversal of 28620445221 is 12254402682.

28620445221 is a `hidden beast` number, since 2 + 8 + 620 + 4 + 4 + 5 + 2 + 21 = 666.

It is not a de Polignac number, because 28620445221 - 2⁹ = 28620444709 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28620445223) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 962056 + ... + 991358.

It is an arithmetic number, because the mean of its divisors is an integer number (1759998240).

Almost surely, 2^28620445221 is an apocalyptic number.

It is an amenable number.

28620445221 is a deficient number, since it is larger than the sum of its proper divisors (13619512539).

28620445221 is a wasteful number, since it uses less digits than its factorization.

28620445221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31665 (or 31662 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 36.

The spelling of 28620445221 in words is "twenty-eight billion, six hundred twenty million, four hundred forty-five thousand, two hundred twenty-one".