21103331218 has 8 divisors (see below), whose sum is σ = 31886055612. Its totient is φ = 10474646016.

The previous prime is 21103331213. The next prime is 21103331237. The reversal of 21103331218 is 81213330112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21047335929 + 55995289 = 145077^2 + 7483^2 .

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

It is a super-2 number, since 2×21103331218² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21103331192 and 21103331201.

It is not an unprimeable number, because it can be changed into a prime (21103331213) by changing a digit.

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, 38509455 + ... + 38510002.

Almost surely, 2^21103331218 is an apocalyptic number.

21103331218 is a deficient number, since it is larger than the sum of its proper divisors (10782724394).

21103331218 is a wasteful number, since it uses less digits than its factorization.

21103331218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77019596.

The product of its (nonzero) digits is 864, while the sum is 25.

The spelling of 21103331218 in words is "twenty-one billion, one hundred three million, three hundred thirty-one thousand, two hundred eighteen".