21211231000 has 96 divisors (see below), whose sum is σ = 50255805600. Its totient is φ = 8379547200.

The previous prime is 21211230949. The next prime is 21211231021. The reversal of 21211231000 is 13211212.

It is a super-2 number, since 2×21211231000² (a number of 21 digits) contains 22 as substring.

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, 6887461 + ... + 6890539.

It is an arithmetic number, because the mean of its divisors is an integer number (523497975).

Almost surely, 2^21211231000 is an apocalyptic number.

21211231000 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 21211231000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25127902800).

21211231000 is an abundant number, since it is smaller than the sum of its proper divisors (29044574600).

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

21211231000 is an equidigital number, since it uses as much as digits as its factorization.

21211231000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3266 (or 3169 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21211231000 its reverse (13211212), we get a palindrome (21224442212).

The spelling of 21211231000 in words is "twenty-one billion, two hundred eleven million, two hundred thirty-one thousand".