21312051373 has 8 divisors (see below), whose sum is σ = 21699268928. Its totient is φ = 20926867104.

The previous prime is 21312051329. The next prime is 21312051379. The reversal of 21312051373 is 37315021312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21312051373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21312051379) 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 7 ways as a sum of consecutive naturals, for example, 487161 + ... + 529102.

It is an arithmetic number, because the mean of its divisors is an integer number (2712408616).

Almost surely, 2^21312051373 is an apocalyptic number.

It is an amenable number.

21312051373 is a deficient number, since it is larger than the sum of its proper divisors (387217555).

21312051373 is a wasteful number, since it uses less digits than its factorization.

21312051373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1016643.

The product of its (nonzero) digits is 3780, while the sum is 28.

Adding to 21312051373 its reverse (37315021312), we get a palindrome (58627072685).

The spelling of 21312051373 in words is "twenty-one billion, three hundred twelve million, fifty-one thousand, three hundred seventy-three".