21021031200 has 216 divisors, whose sum is σ = 74093101488. Its totient is φ = 5174307840.

The previous prime is 21021031193. The next prime is 21021031219. The reversal of 21021031200 is 213012012.

It is a super-2 number, since 2×21021031200² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 379687 + ... + 431513.

It is an arithmetic number, because the mean of its divisors is an integer number (343023618).

Almost surely, 2^21021031200 is an apocalyptic number.

21021031200 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 21021031200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37046550744).

21021031200 is an abundant number, since it is smaller than the sum of its proper divisors (53072070288).

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

21021031200 is a wasteful number, since it uses less digits than its factorization.

21021031200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51876 (or 51850 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21021031200 its reverse (213012012), we get a palindrome (21234043212).

The spelling of 21021031200 in words is "twenty-one billion, twenty-one million, thirty-one thousand, two hundred".