21211696823 has 2 divisors, whose sum is σ = 21211696824. Its totient is φ = 21211696822.

The previous prime is 21211696757. The next prime is 21211696829. The reversal of 21211696823 is 32869611212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21211696823 - 2¹⁸ = 21211434679 is a prime.

It is a super-2 number, since 2×21211696823² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21211696829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605848411 + 10605848412.

It is an arithmetic number, because the mean of its divisors is an integer number (10605848412).

Almost surely, 2^21211696823 is an apocalyptic number.

21211696823 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211696823 is an equidigital number, since it uses as much as digits as its factorization.

21211696823 is an evil number, because the sum of its binary digits is even.

The product of its digits is 62208, while the sum is 41.

The spelling of 21211696823 in words is "twenty-one billion, two hundred eleven million, six hundred ninety-six thousand, eight hundred twenty-three".