21170840818 has 8 divisors (see below), whose sum is σ = 32006310912. Its totient is φ = 10502070516.

The previous prime is 21170840813. The next prime is 21170840851. The reversal of 21170840818 is 81804807112.

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

It is not an unprimeable number, because it can be changed into a prime (21170840813) 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, 41674630 + ... + 41675137.

It is an arithmetic number, because the mean of its divisors is an integer number (4000788864).

Almost surely, 2^21170840818 is an apocalyptic number.

21170840818 is a deficient number, since it is larger than the sum of its proper divisors (10835470094).

21170840818 is a wasteful number, since it uses less digits than its factorization.

21170840818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83349896.

The product of its (nonzero) digits is 28672, while the sum is 40.

The spelling of 21170840818 in words is "twenty-one billion, one hundred seventy million, eight hundred forty thousand, eight hundred eighteen".