21726831418 has 4 divisors (see below), whose sum is σ = 32590247130. Its totient is φ = 10863415708.

The previous prime is 21726831403. The next prime is 21726831421. The reversal of 21726831418 is 81413862712.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 11390652529 + 10336178889 = 106727^2 + 101667^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5431707853 + ... + 5431707856.

Almost surely, 2^21726831418 is an apocalyptic number.

21726831418 is a deficient number, since it is larger than the sum of its proper divisors (10863415712).

21726831418 is a wasteful number, since it uses less digits than its factorization.

21726831418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10863415711.

The product of its digits is 129024, while the sum is 43.

The spelling of 21726831418 in words is "twenty-one billion, seven hundred twenty-six million, eight hundred thirty-one thousand, four hundred eighteen".