21220001331 has 16 divisors (see below), whose sum is σ = 28480112544. Its totient is φ = 14053584384.

The previous prime is 21220001293. The next prime is 21220001357. The reversal of 21220001331 is 13310002212.

It is not a de Polignac number, because 21220001331 - 2⁶ = 21220001267 is a prime.

It is a super-2 number, since 2×21220001331² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21220001331.

It is not an unprimeable number, because it can be changed into a prime (21220001431) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 242161 + ... + 317933.

It is an arithmetic number, because the mean of its divisors is an integer number (1780007034).

Almost surely, 2^21220001331 is an apocalyptic number.

21220001331 is a deficient number, since it is larger than the sum of its proper divisors (7260111213).

21220001331 is a wasteful number, since it uses less digits than its factorization.

21220001331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76390.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21220001331 its reverse (13310002212), we get a palindrome (34530003543).

The spelling of 21220001331 in words is "twenty-one billion, two hundred twenty million, one thousand, three hundred thirty-one".