21211230823 has 2 divisors, whose sum is σ = 21211230824. Its totient is φ = 21211230822.

The previous prime is 21211230797. The next prime is 21211230827. The reversal of 21211230823 is 32803211212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21211230823 - 2¹⁷ = 21211099751 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21211230827) 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, 10605615411 + 10605615412.

It is an arithmetic number, because the mean of its divisors is an integer number (10605615412).

Almost surely, 2^21211230823 is an apocalyptic number.

21211230823 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211230823 is an equidigital number, since it uses as much as digits as its factorization.

21211230823 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 25.

The spelling of 21211230823 in words is "twenty-one billion, two hundred eleven million, two hundred thirty thousand, eight hundred twenty-three".