21221033131 has 4 divisors (see below), whose sum is σ = 21299922000. Its totient is φ = 21142144264.

The previous prime is 21221033111. The next prime is 21221033147. The reversal of 21221033131 is 13133012212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21221033131 - 2⁹ = 21221032619 is a prime.

It is a super-2 number, since 2×21221033131² (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 = 21221033099 and 21221033108.

It is not an unprimeable number, because it can be changed into a prime (21221033111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39444031 + ... + 39444568.

It is an arithmetic number, because the mean of its divisors is an integer number (5324980500).

Almost surely, 2^21221033131 is an apocalyptic number.

21221033131 is a deficient number, since it is larger than the sum of its proper divisors (78888869).

21221033131 is an equidigital number, since it uses as much as digits as its factorization.

21221033131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78888868.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21221033131 its reverse (13133012212), we get a palindrome (34354045343).

The spelling of 21221033131 in words is "twenty-one billion, two hundred twenty-one million, thirty-three thousand, one hundred thirty-one".