21622605 has 16 divisors (see below), whose sum is σ = 34692864. Its totient is φ = 11499840.

The previous prime is 21622591. The next prime is 21622607. The reversal of 21622605 is 50622612.

It is not a de Polignac number, because 21622605 - 2²⁴ = 4845389 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21622607) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4140 + ... + 7770.

It is an arithmetic number, because the mean of its divisors is an integer number (2168304).

Almost surely, 2^21622605 is an apocalyptic number.

It is an amenable number.

21622605 is a deficient number, since it is larger than the sum of its proper divisors (13070259).

21622605 is a wasteful number, since it uses less digits than its factorization.

21622605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4036.

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 21622605 is about 4650.0112903089. The cubic root of 21622605 is about 278.5924471790.

The spelling of 21622605 in words is "twenty-one million, six hundred twenty-two thousand, six hundred five".