21121111112051 has 2 divisors, whose sum is σ = 21121111112052. Its totient is φ = 21121111112050.

The previous prime is 21121111112039. The next prime is 21121111112191. The reversal of 21121111112051 is 15021111112112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21121111112051 - 2²² = 21121106917747 is a prime.

It is a super-2 number, since 2×21121111112051² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21121111112351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560555556025 + 10560555556026.

It is an arithmetic number, because the mean of its divisors is an integer number (10560555556026).

Almost surely, 2^{21121111112051} is an apocalyptic number.

21121111112051 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121111112051 is an equidigital number, since it uses as much as digits as its factorization.

21121111112051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40, while the sum is 20.

Adding to 21121111112051 its reverse (15021111112112), we get a palindrome (36142222224163).

The spelling of 21121111112051 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred eleven million, one hundred twelve thousand, fifty-one".