21625205 has 16 divisors (see below), whose sum is σ = 30460800. Its totient is φ = 14427072.

The previous prime is 21625199. The next prime is 21625229. The reversal of 21625205 is 50252612.

It is a cyclic number.

It is not a de Polignac number, because 21625205 - 2⁴ = 21625189 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, 7055 + ... + 9644.

It is an arithmetic number, because the mean of its divisors is an integer number (1903800).

Almost surely, 2^21625205 is an apocalyptic number.

It is an amenable number.

21625205 is a deficient number, since it is larger than the sum of its proper divisors (8835595).

21625205 is a wasteful number, since it uses less digits than its factorization.

21625205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16748.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 21625205 is about 4650.2908511189. The cubic root of 21625205 is about 278.6036131375.

Adding to 21625205 its reverse (50252612), we get a palindrome (71877817).

The spelling of 21625205 in words is "twenty-one million, six hundred twenty-five thousand, two hundred five".