21221042331 has 16 divisors (see below), whose sum is σ = 28686748160. Its totient is φ = 13951772640.

The previous prime is 21221042329. The next prime is 21221042341. The reversal of 21221042331 is 13324012212.

It is not a de Polignac number, because 21221042331 - 2¹ = 21221042329 is a prime.

It is a super-2 number, since 2×21221042331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21221042298 and 21221042307.

It is not an unprimeable number, because it can be changed into a prime (21221042321) 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, 149676 + ... + 254646.

It is an arithmetic number, because the mean of its divisors is an integer number (1792921760).

Almost surely, 2^21221042331 is an apocalyptic number.

21221042331 is a deficient number, since it is larger than the sum of its proper divisors (7465705829).

21221042331 is a wasteful number, since it uses less digits than its factorization.

21221042331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105906.

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 21221042331 its reverse (13324012212), we get a palindrome (34545054543).

It can be divided in two parts, 212210 and 42331, that added together give a triangular number (254541 = T₇₁₃).

The spelling of 21221042331 in words is "twenty-one billion, two hundred twenty-one million, forty-two thousand, three hundred thirty-one".