21212008969 has 2 divisors, whose sum is σ = 21212008970. Its totient is φ = 21212008968.

The previous prime is 21212008967. The next prime is 21212008999. The reversal of 21212008969 is 96980021212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21072296569 + 139712400 = 145163^2 + 11820^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212008969 - 2¹ = 21212008967 is a prime.

It is a super-2 number, since 2×21212008969² (a number of 21 digits) contains 22 as substring.

Together with 21212008967, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21212008967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606004484 + 10606004485.

It is an arithmetic number, because the mean of its divisors is an integer number (10606004485).

Almost surely, 2^21212008969 is an apocalyptic number.

It is an amenable number.

21212008969 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212008969 is an equidigital number, since it uses as much as digits as its factorization.

21212008969 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 40.

The spelling of 21212008969 in words is "twenty-one billion, two hundred twelve million, eight thousand, nine hundred sixty-nine".