21001122312 has 64 divisors (see below), whose sum is σ = 55624812480. Its totient is φ = 6584604672.

The previous prime is 21001122301. The next prime is 21001122343. The reversal of 21001122312 is 21322110012.

It is a junction number, because it is equal to n+sod(n) for n = 21001122291 and 21001122300.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 700543 + ... + 729905.

It is an arithmetic number, because the mean of its divisors is an integer number (869137695).

Almost surely, 2^21001122312 is an apocalyptic number.

It is an amenable number.

21001122312 is an abundant number, since it is smaller than the sum of its proper divisors (34623690168).

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

21001122312 is a wasteful number, since it uses less digits than its factorization.

21001122312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31142 (or 31138 counting only the distinct ones).

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

Adding to 21001122312 its reverse (21322110012), we get a palindrome (42323232324).

The spelling of 21001122312 in words is "twenty-one billion, one million, one hundred twenty-two thousand, three hundred twelve".