21121046591123 has 2 divisors, whose sum is σ = 21121046591124. Its totient is φ = 21121046591122.

The previous prime is 21121046591089. The next prime is 21121046591201. The reversal of 21121046591123 is 32119564012112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21121046591123 - 2¹⁶ = 21121046525587 is a prime.

It is a super-2 number, since 2×21121046591123² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21121046491123) 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, 10560523295561 + 10560523295562.

It is an arithmetic number, because the mean of its divisors is an integer number (10560523295562).

Almost surely, 2^{21121046591123} is an apocalyptic number.

21121046591123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121046591123 is an equidigital number, since it uses as much as digits as its factorization.

21121046591123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 38.

The spelling of 21121046591123 in words is "twenty-one trillion, one hundred twenty-one billion, forty-six million, five hundred ninety-one thousand, one hundred twenty-three".