28209181821201 has 12 divisors (see below), whose sum is σ = 40798370556112. Its totient is φ = 18782225248536.

The previous prime is 28209181821199. The next prime is 28209181821209. The reversal of 28209181821201 is 10212818190282.

It is a happy number.

28209181821201 is a `hidden beast` number, since 282 + 0 + 91 + 8 + 1 + 82 + 1 + 201 = 666.

It is not a de Polignac number, because 28209181821201 - 2¹ = 28209181821199 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28209181821209) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1991322991 + ... + 1991337156.

Almost surely, 2^{28209181821201} is an apocalyptic number.

It is an amenable number.

28209181821201 is a deficient number, since it is larger than the sum of its proper divisors (12589188734911).

28209181821201 is a wasteful number, since it uses less digits than its factorization.

28209181821201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3982660940 (or 3982660937 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 45.

The spelling of 28209181821201 in words is "twenty-eight trillion, two hundred nine billion, one hundred eighty-one million, eight hundred twenty-one thousand, two hundred one".