21210355452 has 96 divisors (see below), whose sum is σ = 58351313664. Its totient is φ = 5911718400.

The previous prime is 21210355429. The next prime is 21210355457. The reversal of 21210355452 is 25455301212.

It is a super-2 number, since 2×21210355452² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210355457) 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 in 31 ways as a sum of consecutive naturals, for example, 460203 + ... + 504189.

It is an arithmetic number, because the mean of its divisors is an integer number (607826184).

Almost surely, 2^21210355452 is an apocalyptic number.

21210355452 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21210355452, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29175656832).

21210355452 is an abundant number, since it is smaller than the sum of its proper divisors (37140958212).

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

21210355452 is a wasteful number, since it uses less digits than its factorization.

21210355452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44299 (or 44297 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 30.

Adding to 21210355452 its reverse (25455301212), we get a palindrome (46665656664).

The spelling of 21210355452 in words is "twenty-one billion, two hundred ten million, three hundred fifty-five thousand, four hundred fifty-two".