21123100312 has 16 divisors (see below), whose sum is σ = 39644925840. Its totient is φ = 10551120096.

The previous prime is 21123100289. The next prime is 21123100319. The reversal of 21123100312 is 21300132112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21123100319) 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 3 ways as a sum of consecutive naturals, for example, 1295148 + ... + 1311355.

It is an arithmetic number, because the mean of its divisors is an integer number (2477807865).

Almost surely, 2^21123100312 is an apocalyptic number.

It is an amenable number.

21123100312 is a deficient number, since it is larger than the sum of its proper divisors (18521825528).

21123100312 is a wasteful number, since it uses less digits than its factorization.

21123100312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2607522 (or 2607518 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21123100312 its reverse (21300132112), we get a palindrome (42423232424).

The spelling of 21123100312 in words is "twenty-one billion, one hundred twenty-three million, one hundred thousand, three hundred twelve".