21318238730 has 8 divisors (see below), whose sum is σ = 38372829732. Its totient is φ = 8527295488.

The previous prime is 21318238651. The next prime is 21318238741. The reversal of 21318238730 is 3783281312.

It can be written as a sum of positive squares in 2 ways, for example, as 20826241969 + 491996761 = 144313^2 + 22181^2 .

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

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1065911927 + ... + 1065911946.

Almost surely, 2^21318238730 is an apocalyptic number.

21318238730 is a deficient number, since it is larger than the sum of its proper divisors (17054591002).

21318238730 is a wasteful number, since it uses less digits than its factorization.

21318238730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2131823880.

The product of its (nonzero) digits is 48384, while the sum is 38.

The spelling of 21318238730 in words is "twenty-one billion, three hundred eighteen million, two hundred thirty-eight thousand, seven hundred thirty".