21021111131 has 2 divisors, whose sum is σ = 21021111132. Its totient is φ = 21021111130.

The previous prime is 21021111049. The next prime is 21021111169. The reversal of 21021111131 is 13111112012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21021111131 - 2³⁴ = 3841241947 is a prime.

It is a super-2 number, since 2×21021111131² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21021119131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510555565 + 10510555566.

It is an arithmetic number, because the mean of its divisors is an integer number (10510555566).

Almost surely, 2^21021111131 is an apocalyptic number.

21021111131 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021111131 is an equidigital number, since it uses as much as digits as its factorization.

21021111131 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12, while the sum is 14.

Adding to 21021111131 its reverse (13111112012), we get a palindrome (34132223143).

The spelling of 21021111131 in words is "twenty-one billion, twenty-one million, one hundred eleven thousand, one hundred thirty-one".