21212333352 has 128 divisors (see below), whose sum is σ = 67995033600. Its totient is φ = 6001781184.

The previous prime is 21212333341. The next prime is 21212333383. The reversal of 21212333352 is 25333321212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 87633 + ... + 223839.

It is an arithmetic number, because the mean of its divisors is an integer number (531211200).

Almost surely, 2^21212333352 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21212333352, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33997516800).

21212333352 is an abundant number, since it is smaller than the sum of its proper divisors (46782700248).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21212333352 is a wasteful number, since it uses less digits than its factorization.

21212333352 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136332 (or 136322 counting only the distinct ones).

The product of its digits is 6480, while the sum is 27.

Adding to 21212333352 its reverse (25333321212), we get a palindrome (46545654564).

The spelling of 21212333352 in words is "twenty-one billion, two hundred twelve million, three hundred thirty-three thousand, three hundred fifty-two".