21000000132221 has 6 divisors (see below), whose sum is σ = 23082644773566. Its totient is φ = 19090909211000.

The previous prime is 21000000132149. The next prime is 21000000132239. The reversal of 21000000132221 is 12223100000012.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 19597788909721 + 1402211222500 = 4426939^2 + 1184150^2 .

It is not a de Polignac number, because 21000000132221 - 2¹⁰ = 21000000131197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21000000132196 and 21000000132205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000000132121) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 86776859930 + ... + 86776860171.

It is an arithmetic number, because the mean of its divisors is an integer number (3847107462261).

Almost surely, 2^{21000000132221} is an apocalyptic number.

It is an amenable number.

21000000132221 is a deficient number, since it is larger than the sum of its proper divisors (2082644641345).

21000000132221 is a wasteful number, since it uses less digits than its factorization.

21000000132221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173553720123 (or 173553720112 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21000000132221 its reverse (12223100000012), we get a palindrome (33223100132233).

The spelling of 21000000132221 in words is "twenty-one trillion, one hundred thirty-two thousand, two hundred twenty-one".