21232042221 has 16 divisors (see below), whose sum is σ = 30501394560. Its totient is φ = 13059718080.

The previous prime is 21232042217. The next prime is 21232042231. The reversal of 21232042221 is 12224023212.

It is not a de Polignac number, because 21232042221 - 2² = 21232042217 is a prime.

It is a super-2 number, since 2×21232042221² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21232042211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43641 + ... + 210638.

It is an arithmetic number, because the mean of its divisors is an integer number (1906337160).

Almost surely, 2^21232042221 is an apocalyptic number.

It is an amenable number.

21232042221 is a deficient number, since it is larger than the sum of its proper divisors (9269352339).

21232042221 is a wasteful number, since it uses less digits than its factorization.

21232042221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256436.

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21232042221 its reverse (12224023212), we get a palindrome (33456065433).

It can be divided in two parts, 212320 and 42221, that added together give a triangular number (254541 = T₇₁₃).

The spelling of 21232042221 in words is "twenty-one billion, two hundred thirty-two million, forty-two thousand, two hundred twenty-one".