21311011300 has 72 divisors (see below), whose sum is σ = 48998254536. Its totient is φ = 8017551360.

The previous prime is 21311011297. The next prime is 21311011303. The reversal of 21311011300 is 311011312.

It is an interprime number because it is at equal distance from previous prime (21311011297) and next prime (21311011303).

It can be written as a sum of positive squares in 12 ways, for example, as 1409702116 + 19901309184 = 37546^2 + 141072^2 .

It is not an unprimeable number, because it can be changed into a prime (21311011303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3248824 + ... + 3255376.

It is an arithmetic number, because the mean of its divisors is an integer number (680531313).

Almost surely, 2^21311011300 is an apocalyptic number.

21311011300 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 21311011300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24499127268).

21311011300 is an abundant number, since it is smaller than the sum of its proper divisors (27687243236).

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

21311011300 is a wasteful number, since it uses less digits than its factorization.

21311011300 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8497 (or 8490 counting only the distinct ones).

The product of its (nonzero) digits is 18, while the sum is 13.

Adding to 21311011300 its reverse (311011312), we get a palindrome (21622022612).

The spelling of 21311011300 in words is "twenty-one billion, three hundred eleven million, eleven thousand, three hundred".