21212021959 has 2 divisors, whose sum is σ = 21212021960. Its totient is φ = 21212021958.

The previous prime is 21212021947. The next prime is 21212022019. The reversal of 21212021959 is 95912021212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21212021959 - 2⁵ = 21212021927 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21212021459) 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, 10606010979 + 10606010980.

It is an arithmetic number, because the mean of its divisors is an integer number (10606010980).

Almost surely, 2^21212021959 is an apocalyptic number.

21212021959 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212021959 is an equidigital number, since it uses as much as digits as its factorization.

21212021959 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 34.

The spelling of 21212021959 in words is "twenty-one billion, two hundred twelve million, twenty-one thousand, nine hundred fifty-nine".