28901497221 has 16 divisors (see below), whose sum is σ = 42825117120. Its totient is φ = 19264026960.

The previous prime is 28901497199. The next prime is 28901497279. The reversal of 28901497221 is 12279410982.

28901497221 is a `hidden beast` number, since 289 + 0 + 149 + 7 + 221 = 666.

It is not a de Polignac number, because 28901497221 - 2²⁷ = 28767279493 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28901497621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48631 + ... + 245291.

It is an arithmetic number, because the mean of its divisors is an integer number (2676569820).

Almost surely, 2^28901497221 is an apocalyptic number.

It is an amenable number.

28901497221 is a deficient number, since it is larger than the sum of its proper divisors (13923619899).

28901497221 is a wasteful number, since it uses less digits than its factorization.

28901497221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202113 (or 202107 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The spelling of 28901497221 in words is "twenty-eight billion, nine hundred one million, four hundred ninety-seven thousand, two hundred twenty-one".