21361625205 has 16 divisors (see below), whose sum is σ = 34198364160. Its totient is φ = 11386278848.

The previous prime is 21361625189. The next prime is 21361625317. The reversal of 21361625205 is 50252616312.

It is a cyclic number.

It is not a de Polignac number, because 21361625205 - 2⁴ = 21361625189 is a prime.

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, 384885 + ... + 436874.

It is an arithmetic number, because the mean of its divisors is an integer number (2137397760).

Almost surely, 2^21361625205 is an apocalyptic number.

It is an amenable number.

21361625205 is a deficient number, since it is larger than the sum of its proper divisors (12836738955).

21361625205 is a wasteful number, since it uses less digits than its factorization.

21361625205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 823500.

The product of its (nonzero) digits is 21600, while the sum is 33.

The spelling of 21361625205 in words is "twenty-one billion, three hundred sixty-one million, six hundred twenty-five thousand, two hundred five".