21022131 has 16 divisors (see below), whose sum is σ = 30502304. Its totient is φ = 12801024.

The previous prime is 21022117. The next prime is 21022163. The reversal of 21022131 is 13122012.

It is not a de Polignac number, because 21022131 - 2¹⁰ = 21021107 is a prime.

It is a super-2 number, since 2×21022131² = 883859983562322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21022171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1005 + ... + 6561.

It is an arithmetic number, because the mean of its divisors is an integer number (1906394).

Almost surely, 2^21022131 is an apocalyptic number.

21022131 is a deficient number, since it is larger than the sum of its proper divisors (9480173).

21022131 is a wasteful number, since it uses less digits than its factorization.

21022131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5670.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 21022131 is about 4584.9897491707. The cubic root of 21022131 is about 275.9893006774.

Adding to 21022131 its reverse (13122012), we get a palindrome (34144143).

The spelling of 21022131 in words is "twenty-one million, twenty-two thousand, one hundred thirty-one".