21312208843 has 2 divisors, whose sum is σ = 21312208844. Its totient is φ = 21312208842.

The previous prime is 21312208807. The next prime is 21312208867. The reversal of 21312208843 is 34880221312.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21312208843 - 2²⁹ = 20775337931 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21312208799 and 21312208808.

It is not a weakly prime, because it can be changed into another prime (21312268843) 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, 10656104421 + 10656104422.

It is an arithmetic number, because the mean of its divisors is an integer number (10656104422).

Almost surely, 2^21312208843 is an apocalyptic number.

21312208843 is a deficient number, since it is larger than the sum of its proper divisors (1).

21312208843 is an equidigital number, since it uses as much as digits as its factorization.

21312208843 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18432, while the sum is 34.

The spelling of 21312208843 in words is "twenty-one billion, three hundred twelve million, two hundred eight thousand, eight hundred forty-three".