21001033312 has 48 divisors (see below), whose sum is σ = 48257717760. Its totient is φ = 8808939648.

The previous prime is 21001033267. The next prime is 21001033321. The reversal of 21001033312 is 21333010012.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 986862 + ... + 1007917.

It is an arithmetic number, because the mean of its divisors is an integer number (1005369120).

Almost surely, 2^21001033312 is an apocalyptic number.

It is an amenable number.

21001033312 is an abundant number, since it is smaller than the sum of its proper divisors (27256684448).

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

21001033312 is a wasteful number, since it uses less digits than its factorization.

21001033312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1994843 (or 1994835 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 16.

Adding to 21001033312 its reverse (21333010012), we get a palindrome (42334043324).

The spelling of 21001033312 in words is "twenty-one billion, one million, thirty-three thousand, three hundred twelve".