21055105140 has 48 divisors (see below), whose sum is σ = 60856051200. Its totient is φ = 5433575040.

The previous prime is 21055105139. The next prime is 21055105157. The reversal of 21055105140 is 4150155012.

It is a self number, because there is not a number n which added to its sum of digits gives 21055105140.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5658115 + ... + 5661834.

It is an arithmetic number, because the mean of its divisors is an integer number (1267834400).

Almost surely, 2^21055105140 is an apocalyptic number.

21055105140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21055105140 is an abundant number, since it is smaller than the sum of its proper divisors (39800946060).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21055105140 is a wasteful number, since it uses less digits than its factorization.

21055105140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11319992 (or 11319990 counting only the distinct ones).

The product of its (nonzero) digits is 1000, while the sum is 24.

The spelling of 21055105140 in words is "twenty-one billion, fifty-five million, one hundred five thousand, one hundred forty".