21406108550 has 12 divisors (see below), whose sum is σ = 39815361996. Its totient is φ = 8562443400.

The previous prime is 21406108547. The next prime is 21406108589. The reversal of 21406108550 is 5580160412.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 214061036 + ... + 214061135.

It is an arithmetic number, because the mean of its divisors is an integer number (3317946833).

Almost surely, 2^21406108550 is an apocalyptic number.

21406108550 is a deficient number, since it is larger than the sum of its proper divisors (18409253446).

21406108550 is a wasteful number, since it uses less digits than its factorization.

21406108550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 428122183 (or 428122178 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 32.

Adding to 21406108550 its reverse (5580160412), we get a palindrome (26986268962).

The spelling of 21406108550 in words is "twenty-one billion, four hundred six million, one hundred eight thousand, five hundred fifty".