21122121131 has 2 divisors, whose sum is σ = 21122121132. Its totient is φ = 21122121130.

The previous prime is 21122121103. The next prime is 21122121161. The reversal of 21122121131 is 13112122112.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21122121131 - 2¹⁴ = 21122104747 is a prime.

It is a super-2 number, since 2×21122121131² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21122121101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561060565 + 10561060566.

It is an arithmetic number, because the mean of its divisors is an integer number (10561060566).

Almost surely, 2^21122121131 is an apocalyptic number.

21122121131 is a deficient number, since it is larger than the sum of its proper divisors (1).

21122121131 is an equidigital number, since it uses as much as digits as its factorization.

21122121131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48, while the sum is 17.

Adding to 21122121131 its reverse (13112122112), we get a palindrome (34234243243).

The spelling of 21122121131 in words is "twenty-one billion, one hundred twenty-two million, one hundred twenty-one thousand, one hundred thirty-one".