28721294226 has 32 divisors (see below), whose sum is σ = 63902937600. Its totient is φ = 9562088880.

The previous prime is 28721294207. The next prime is 28721294227. The reversal of 28721294226 is 62249212782.

28721294226 is a `hidden beast` number, since 2 + 8 + 7 + 212 + 9 + 422 + 6 = 666.

28721294226 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (28721294227) 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, 279586 + ... + 368253.

It is an arithmetic number, because the mean of its divisors is an integer number (1996966800).

Almost surely, 2^28721294226 is an apocalyptic number.

28721294226 is an abundant number, since it is smaller than the sum of its proper divisors (35181643374).

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

28721294226 is a wasteful number, since it uses less digits than its factorization.

28721294226 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 648671 (or 648665 counting only the distinct ones).

The product of its digits is 387072, while the sum is 45.

The spelling of 28721294226 in words is "twenty-eight billion, seven hundred twenty-one million, two hundred ninety-four thousand, two hundred twenty-six".