21011023200 has 144 divisors (see below), whose sum is σ = 69681696336. Its totient is φ = 5497190400.

The previous prime is 21011023133. The next prime is 21011023211. The reversal of 21011023200 is 232011012.

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

It is a congruent number.

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, 44610 + ... + 209790.

It is an arithmetic number, because the mean of its divisors is an integer number (483900669).

Almost surely, 2^21011023200 is an apocalyptic number.

21011023200 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 21011023200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34840848168).

21011023200 is an abundant number, since it is smaller than the sum of its proper divisors (48670673136).

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

21011023200 is a wasteful number, since it uses less digits than its factorization.

21011023200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165257 (or 165244 counting only the distinct ones).

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

Adding to 21011023200 its reverse (232011012), we get a palindrome (21243034212).

The spelling of 21011023200 in words is "twenty-one billion, eleven million, twenty-three thousand, two hundred".