21905043108 has 48 divisors (see below), whose sum is σ = 55055145600. Its totient is φ = 6738580224.

The previous prime is 21905043079. The next prime is 21905043137. The reversal of 21905043108 is 80134050912.

It is an interprime number because it is at equal distance from previous prime (21905043079) and next prime (21905043137).

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, 900441 + ... + 924447.

It is an arithmetic number, because the mean of its divisors is an integer number (1146982200).

Almost surely, 2^21905043108 is an apocalyptic number.

It is an amenable number.

21905043108 is an abundant number, since it is smaller than the sum of its proper divisors (33150102492).

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

21905043108 is a wasteful number, since it uses less digits than its factorization.

21905043108 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29876 (or 29874 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 33.

The spelling of 21905043108 in words is "twenty-one billion, nine hundred five million, forty-three thousand, one hundred eight".