21843578738 has 8 divisors (see below), whose sum is σ = 33214208988. Its totient is φ = 10772175744.

The previous prime is 21843578723. The next prime is 21843578777. The reversal of 21843578738 is 83787534812.

It can be written as a sum of positive squares in 2 ways, for example, as 21606942049 + 236636689 = 146993^2 + 15383^2 .

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, 74806631 + ... + 74806922.

Almost surely, 2^21843578738 is an apocalyptic number.

21843578738 is a deficient number, since it is larger than the sum of its proper divisors (11370630250).

21843578738 is a wasteful number, since it uses less digits than its factorization.

21843578738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149613628.

The product of its digits is 9031680, while the sum is 56.

The spelling of 21843578738 in words is "twenty-one billion, eight hundred forty-three million, five hundred seventy-eight thousand, seven hundred thirty-eight".