21785338554 has 48 divisors (see below), whose sum is σ = 53351863200. Its totient is φ = 5896781856.

The previous prime is 21785338529. The next prime is 21785338609. The reversal of 21785338554 is 45583358712.

It is a happy number.

21785338554 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 21785338497 and 21785338506.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1944409 + ... + 1955580.

It is an arithmetic number, because the mean of its divisors is an integer number (1111497150).

Almost surely, 2^21785338554 is an apocalyptic number.

21785338554 is an abundant number, since it is smaller than the sum of its proper divisors (31566524646).

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

21785338554 is a wasteful number, since it uses less digits than its factorization.

21785338554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3900027 (or 3900020 counting only the distinct ones).

The product of its digits is 4032000, while the sum is 51.

The spelling of 21785338554 in words is "twenty-one billion, seven hundred eighty-five million, three hundred thirty-eight thousand, five hundred fifty-four".