21212404323 has 8 divisors (see below), whose sum is σ = 30854406336. Its totient is φ = 12856002600.

The previous prime is 21212404307. The next prime is 21212404331. The reversal of 21212404323 is 32340421212.

It is a happy number.

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

It is not a de Polignac number, because 21212404323 - 2⁴ = 21212404307 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21212404293 and 21212404302.

It is not an unprimeable number, because it can be changed into a prime (21212404363) 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, 321400033 + ... + 321400098.

It is an arithmetic number, because the mean of its divisors is an integer number (3856800792).

Almost surely, 2^21212404323 is an apocalyptic number.

21212404323 is a deficient number, since it is larger than the sum of its proper divisors (9642002013).

21212404323 is a wasteful number, since it uses less digits than its factorization.

21212404323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 642800145.

The product of its (nonzero) digits is 2304, while the sum is 24.

Adding to 21212404323 its reverse (32340421212), we get a palindrome (53552825535).

The spelling of 21212404323 in words is "twenty-one billion, two hundred twelve million, four hundred four thousand, three hundred twenty-three".