21381818312 has 16 divisors (see below), whose sum is σ = 40598390400. Its totient is φ = 10555580880.

The previous prime is 21381818243. The next prime is 21381818317.

21381818312 is nontrivially palindromic in base 10.

It is not an unprimeable number, because it can be changed into a prime (21381818317) 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, 16915364 + ... + 16916627.

It is an arithmetic number, because the mean of its divisors is an integer number (2537399400).

Almost surely, 2^21381818312 is an apocalyptic number.

It is an amenable number.

21381818312 is a deficient number, since it is larger than the sum of its proper divisors (19216572088).

21381818312 is a wasteful number, since it uses less digits than its factorization.

21381818312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33832076 (or 33832072 counting only the distinct ones).

The product of its digits is 18432, while the sum is 38.

The spelling of 21381818312 in words is "twenty-one billion, three hundred eighty-one million, eight hundred eighteen thousand, three hundred twelve".