21055031200 has 144 divisors (see below), whose sum is σ = 58837484160. Its totient is φ = 7207326720.

The previous prime is 21055031161. The next prime is 21055031213. The reversal of 21055031200 is 213055012.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3967749 + ... + 3973051.

It is an arithmetic number, because the mean of its divisors is an integer number (408593640).

Almost surely, 2^21055031200 is an apocalyptic number.

21055031200 is a gapful number since it is divisible by the number (20) 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 21055031200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29418742080).

21055031200 is an abundant number, since it is smaller than the sum of its proper divisors (37782452960).

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

21055031200 is a wasteful number, since it uses less digits than its factorization.

21055031200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6039 (or 6026 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 19.

Adding to 21055031200 its reverse (213055012), we get a palindrome (21268086212).

It can be divided in two parts, 2105 and 5031200, that added together give a palindrome (5033305).

The spelling of 21055031200 in words is "twenty-one billion, fifty-five million, thirty-one thousand, two hundred".