28220641309 has 16 divisors (see below), whose sum is σ = 33957273600. Its totient is φ = 22910859504.

The previous prime is 28220641297. The next prime is 28220641313. The reversal of 28220641309 is 90314602282.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 28220641309 - 2⁹ = 28220640797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28220641909) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 639252 + ... + 681970.

It is an arithmetic number, because the mean of its divisors is an integer number (2122329600).

Almost surely, 2^28220641309 is an apocalyptic number.

It is an amenable number.

28220641309 is a deficient number, since it is larger than the sum of its proper divisors (5736632291).

28220641309 is a wasteful number, since it uses less digits than its factorization.

28220641309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47712.

The product of its (nonzero) digits is 41472, while the sum is 37.

The spelling of 28220641309 in words is "twenty-eight billion, two hundred twenty million, six hundred forty-one thousand, three hundred nine".