21321223523 has 8 divisors (see below), whose sum is σ = 22798933920. Its totient is φ = 19868348800.

The previous prime is 21321223477. The next prime is 21321223543. The reversal of 21321223523 is 32532212312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21321223523 - 2⁸ = 21321223267 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21321223492 and 21321223501.

It is not an unprimeable number, because it can be changed into a prime (21321223543) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6207143 + ... + 6210576.

It is an arithmetic number, because the mean of its divisors is an integer number (2849866740).

Almost surely, 2^21321223523 is an apocalyptic number.

21321223523 is a deficient number, since it is larger than the sum of its proper divisors (1477710397).

21321223523 is a wasteful number, since it uses less digits than its factorization.

21321223523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12417837.

The product of its digits is 4320, while the sum is 26.

Adding to 21321223523 its reverse (32532212312), we get a palindrome (53853435835).

The spelling of 21321223523 in words is "twenty-one billion, three hundred twenty-one million, two hundred twenty-three thousand, five hundred twenty-three".