21121023420487 has 2 divisors, whose sum is σ = 21121023420488. Its totient is φ = 21121023420486.

The previous prime is 21121023420403. The next prime is 21121023420583. The reversal of 21121023420487 is 78402432012112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21121023420487 - 2⁷ = 21121023420359 is a prime.

It is a super-2 number, since 2×21121023420487² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21121023120487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560511710243 + 10560511710244.

It is an arithmetic number, because the mean of its divisors is an integer number (10560511710244).

Almost surely, 2^{21121023420487} is an apocalyptic number.

21121023420487 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121023420487 is an equidigital number, since it uses as much as digits as its factorization.

21121023420487 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43008, while the sum is 37.

Adding to 21121023420487 its reverse (78402432012112), we get a palindrome (99523455432599).

The spelling of 21121023420487 in words is "twenty-one trillion, one hundred twenty-one billion, twenty-three million, four hundred twenty thousand, four hundred eighty-seven".