21085618124 has 12 divisors (see below), whose sum is σ = 36900893400. Its totient is φ = 10542505728.

The previous prime is 21085618111. The next prime is 21085618241. The reversal of 21085618124 is 42181658012.

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, 166892 + ... + 264620.

It is an arithmetic number, because the mean of its divisors is an integer number (3075074450).

Almost surely, 2^21085618124 is an apocalyptic number.

It is an amenable number.

21085618124 is a deficient number, since it is larger than the sum of its proper divisors (15815275276).

21085618124 is a wasteful number, since it uses less digits than its factorization.

21085618124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151672 (or 151670 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 38.

The spelling of 21085618124 in words is "twenty-one billion, eighty-five million, six hundred eighteen thousand, one hundred twenty-four".