21312543442 has 8 divisors (see below), whose sum is σ = 33849333756. Its totient is φ = 10029432192.

The previous prime is 21312543379. The next prime is 21312543451. The reversal of 21312543442 is 24434521312.

It can be written as a sum of positive squares in 2 ways, for example, as 19754583601 + 1557959841 = 140551^2 + 39471^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 313419723 + ... + 313419790.

Almost surely, 2^21312543442 is an apocalyptic number.

21312543442 is a deficient number, since it is larger than the sum of its proper divisors (12536790314).

21312543442 is a wasteful number, since it uses less digits than its factorization.

21312543442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 626839532.

The product of its digits is 23040, while the sum is 31.

The spelling of 21312543442 in words is "twenty-one billion, three hundred twelve million, five hundred forty-three thousand, four hundred forty-two".