21203120312 has 32 divisors (see below), whose sum is σ = 43919020800. Its totient is φ = 9515781600.

The previous prime is 21203120299. The next prime is 21203120347. The reversal of 21203120312 is 21302130212.

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, 1518014 + ... + 1531917.

It is an arithmetic number, because the mean of its divisors is an integer number (1372469400).

Almost surely, 2^21203120312 is an apocalyptic number.

21203120312 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21203120312 is an abundant number, since it is smaller than the sum of its proper divisors (22715900488).

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

21203120312 is a wasteful number, since it uses less digits than its factorization.

21203120312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3050027 (or 3050023 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21203120312 its reverse (21302130212), we get a palindrome (42505250524).

The spelling of 21203120312 in words is "twenty-one billion, two hundred three million, one hundred twenty thousand, three hundred twelve".