21012200104 has 64 divisors (see below), whose sum is σ = 45586800000. Its totient is φ = 8893344768.

The previous prime is 21012200101. The next prime is 21012200119. The reversal of 21012200104 is 40100221012.

It is a happy number.

It is a super-2 number, since 2×21012200104² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21012200101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5226207 + ... + 5230225.

It is an arithmetic number, because the mean of its divisors is an integer number (712293750).

Almost surely, 2^21012200104 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21012200104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22793400000).

21012200104 is an abundant number, since it is smaller than the sum of its proper divisors (24574599896).

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

21012200104 is a wasteful number, since it uses less digits than its factorization.

21012200104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5170 (or 5166 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21012200104 its reverse (40100221012), we get a palindrome (61112421116).

The spelling of 21012200104 in words is "twenty-one billion, twelve million, two hundred thousand, one hundred four".