28021255938 has 32 divisors (see below), whose sum is σ = 67059417600. Its totient is φ = 8621924688.

The previous prime is 28021255931. The next prime is 28021255939. The reversal of 28021255938 is 83955212082.

28021255938 is a `hidden beast` number, since 2 + 80 + 2 + 12 + 559 + 3 + 8 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 28021255893 and 28021255902.

It is not an unprimeable number, because it can be changed into a prime (28021255931) 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, 19957458 + ... + 19958861.

It is an arithmetic number, because the mean of its divisors is an integer number (2095606800).

Almost surely, 2^28021255938 is an apocalyptic number.

28021255938 is an abundant number, since it is smaller than the sum of its proper divisors (39038161662).

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

28021255938 is a wasteful number, since it uses less digits than its factorization.

28021255938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39916343 (or 39916337 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 45.

The spelling of 28021255938 in words is "twenty-eight billion, twenty-one million, two hundred fifty-five thousand, nine hundred thirty-eight".