21301221012 has 96 divisors (see below), whose sum is σ = 53355020544. Its totient is φ = 6597043200.

The previous prime is 21301221001. The next prime is 21301221023. The reversal of 21301221012 is 21012210312.

It is an interprime number because it is at equal distance from previous prime (21301221001) and next prime (21301221023).

It is a junction number, because it is equal to n+sod(n) for n = 21301220982 and 21301221000.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 7769962 + ... + 7772702.

It is an arithmetic number, because the mean of its divisors is an integer number (555781464).

Almost surely, 2^21301221012 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 21301221012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26677510272).

21301221012 is an abundant number, since it is smaller than the sum of its proper divisors (32053799532).

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

21301221012 is a wasteful number, since it uses less digits than its factorization.

21301221012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3569 (or 3567 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21301221012 its reverse (21012210312), we get a palindrome (42313431324).

The spelling of 21301221012 in words is "twenty-one billion, three hundred one million, two hundred twenty-one thousand, twelve".