21201072284 has 24 divisors (see below), whose sum is σ = 43436345568. Its totient is φ = 8864559360.

The previous prime is 21201072241. The next prime is 21201072301. The reversal of 21201072284 is 48227010212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9232769 + ... + 9235064.

It is an arithmetic number, because the mean of its divisors is an integer number (1809847732).

Almost surely, 2^21201072284 is an apocalyptic number.

It is an amenable number.

21201072284 is an abundant number, since it is smaller than the sum of its proper divisors (22235273284).

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

21201072284 is a wasteful number, since it uses less digits than its factorization.

21201072284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18467885 (or 18467883 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 29.

Adding to 21201072284 its reverse (48227010212), we get a palindrome (69428082496).

The spelling of 21201072284 in words is "twenty-one billion, two hundred one million, seventy-two thousand, two hundred eighty-four".