21259972871 has 2 divisors, whose sum is σ = 21259972872. Its totient is φ = 21259972870.

The previous prime is 21259972861. The next prime is 21259972891. The reversal of 21259972871 is 17827995212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21259972871 - 2¹⁰ = 21259971847 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21259972801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10629986435 + 10629986436.

It is an arithmetic number, because the mean of its divisors is an integer number (10629986436).

Almost surely, 2^21259972871 is an apocalyptic number.

21259972871 is a deficient number, since it is larger than the sum of its proper divisors (1).

21259972871 is an equidigital number, since it uses as much as digits as its factorization.

21259972871 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1270080, while the sum is 53.

The spelling of 21259972871 in words is "twenty-one billion, two hundred fifty-nine million, nine hundred seventy-two thousand, eight hundred seventy-one".