21120023987 has 2 divisors, whose sum is σ = 21120023988. Its totient is φ = 21120023986.

The previous prime is 21120023963. The next prime is 21120024067. The reversal of 21120023987 is 78932002112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21120023987 - 2¹⁴ = 21120007603 is a prime.

It is a super-2 number, since 2×21120023987² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21120053987) 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, 10560011993 + 10560011994.

It is an arithmetic number, because the mean of its divisors is an integer number (10560011994).

Almost surely, 2^21120023987 is an apocalyptic number.

21120023987 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120023987 is an equidigital number, since it uses as much as digits as its factorization.

21120023987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12096, while the sum is 35.

The spelling of 21120023987 in words is "twenty-one billion, one hundred twenty million, twenty-three thousand, nine hundred eighty-seven".