21061818608 has 20 divisors (see below), whose sum is σ = 40809528648. Its totient is φ = 10530327360.

The previous prime is 21061818587. The next prime is 21061818641. The reversal of 21061818608 is 80681816012.

It is a congruent 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, 521510 + ... + 560442.

Almost surely, 2^21061818608 is an apocalyptic number.

It is an amenable number.

21061818608 is a deficient number, since it is larger than the sum of its proper divisors (19747710040).

21061818608 is a wasteful number, since it uses less digits than its factorization.

21061818608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72752 (or 72746 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 41.

The spelling of 21061818608 in words is "twenty-one billion, sixty-one million, eight hundred eighteen thousand, six hundred eight".