21101211000 has 192 divisors, whose sum is σ = 73250873280. Its totient is φ = 5474822400.

The previous prime is 21101210959. The next prime is 21101211059. The reversal of 21101211000 is 11210112.

It is a happy number.

It is a super-2 number, since 2×21101211000² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 301317 + ... + 364683.

It is an arithmetic number, because the mean of its divisors is an integer number (381514965).

Almost surely, 2^21101211000 is an apocalyptic number.

21101211000 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 21101211000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36625436640).

21101211000 is an abundant number, since it is smaller than the sum of its proper divisors (52149662280).

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

21101211000 is a wasteful number, since it uses less digits than its factorization.

21101211000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63431 (or 63414 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21101211000 its reverse (11210112), we get a palindrome (21112421112).

The spelling of 21101211000 in words is "twenty-one billion, one hundred one million, two hundred eleven thousand".