28988719221 has 64 divisors (see below), whose sum is σ = 48512471040. Its totient is φ = 14958397440.

The previous prime is 28988719219. The next prime is 28988719229. The reversal of 28988719221 is 12291788982.

It is not a de Polignac number, because 28988719221 - 2¹ = 28988719219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28988719229) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 40886415 + ... + 40887123.

It is an arithmetic number, because the mean of its divisors is an integer number (758007360).

Almost surely, 2^28988719221 is an apocalyptic number.

28988719221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

28988719221 is a deficient number, since it is larger than the sum of its proper divisors (19523751819).

28988719221 is a wasteful number, since it uses less digits than its factorization.

28988719221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1666.

The product of its digits is 2322432, while the sum is 57.

It can be divided in two parts, 2898871 and 9221, that added together give a palindrome (2908092).

The spelling of 28988719221 in words is "twenty-eight billion, nine hundred eighty-eight million, seven hundred nineteen thousand, two hundred twenty-one".