21489363823 has 2 divisors, whose sum is σ = 21489363824. Its totient is φ = 21489363822.

The previous prime is 21489363817. The next prime is 21489363881. The reversal of 21489363823 is 32836398412.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21489363823 is a prime.

It is a super-2 number, since 2×21489363823² (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 (21489363023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10744681911 + 10744681912.

It is an arithmetic number, because the mean of its divisors is an integer number (10744681912).

Almost surely, 2^21489363823 is an apocalyptic number.

21489363823 is a deficient number, since it is larger than the sum of its proper divisors (1).

21489363823 is an equidigital number, since it uses as much as digits as its factorization.

21489363823 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1492992, while the sum is 49.

The spelling of 21489363823 in words is "twenty-one billion, four hundred eighty-nine million, three hundred sixty-three thousand, eight hundred twenty-three".