21011222001000 has 1024 divisors, whose sum is σ = 84229217280000. Its totient is φ = 4322505600000.

The previous prime is 21011222000953. The next prime is 21011222001047. The reversal of 21011222001000 is 10022211012.

It is an interprime number because it is at equal distance from previous prime (21011222000953) and next prime (21011222001047).

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 255 ways as a sum of consecutive naturals, for example, 1143209811 + ... + 1143228189.

It is an arithmetic number, because the mean of its divisors is an integer number (82255095000).

Almost surely, 2^{21011222001000} is an apocalyptic number.

21011222001000 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 21011222001000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42114608640000).

21011222001000 is an abundant number, since it is smaller than the sum of its proper divisors (63217995279000).

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

21011222001000 is a wasteful number, since it uses less digits than its factorization.

21011222001000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18536 (or 18508 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21011222001000 its reverse (10022211012), we get a palindrome (21021244212012).

The spelling of 21011222001000 in words is "twenty-one trillion, eleven billion, two hundred twenty-two million, one thousand".