28076872221 has 24 divisors (see below), whose sum is σ = 40993505280. Its totient is φ = 18516837600.

The previous prime is 28076872183. The next prime is 28076872247. The reversal of 28076872221 is 12227867082.

28076872221 is a `hidden beast` number, since 280 + 76 + 87 + 2 + 221 = 666.

It is not a de Polignac number, because 28076872221 - 2⁶ = 28076872157 is a prime.

It is a super-2 number, since 2×28076872221² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28076862221) 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, 266020 + ... + 356258.

It is an arithmetic number, because the mean of its divisors is an integer number (1708062720).

Almost surely, 2^28076872221 is an apocalyptic number.

It is an amenable number.

28076872221 is a deficient number, since it is larger than the sum of its proper divisors (12916633059).

28076872221 is a wasteful number, since it uses less digits than its factorization.

28076872221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90617 (or 90614 counting only the distinct ones).

The product of its (nonzero) digits is 301056, while the sum is 45.

The spelling of 28076872221 in words is "twenty-eight billion, seventy-six million, eight hundred seventy-two thousand, two hundred twenty-one".