21980435221 has 8 divisors (see below), whose sum is σ = 22344018840. Its totient is φ = 21619795968.

The previous prime is 21980435167. The next prime is 21980435227. The reversal of 21980435221 is 12253408912.

It can be written as a sum of positive squares in 4 ways, for example, as 5773872196 + 16206563025 = 75986^2 + 127305^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21980435221 - 2¹¹ = 21980433173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21980435227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 721036 + ... + 750901.

It is an arithmetic number, because the mean of its divisors is an integer number (2793002355).

Almost surely, 2^21980435221 is an apocalyptic number.

It is an amenable number.

21980435221 is a deficient number, since it is larger than the sum of its proper divisors (363583619).

21980435221 is a wasteful number, since it uses less digits than its factorization.

21980435221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1472183.

The product of its (nonzero) digits is 34560, while the sum is 37.

It can be divided in two parts, 219804 and 35221, that added together give a square (255025 = 505²).

The spelling of 21980435221 in words is "twenty-one billion, nine hundred eighty million, four hundred thirty-five thousand, two hundred twenty-one".