21905195 has 16 divisors (see below), whose sum is σ = 29799840. Its totient is φ = 15323904.

The previous prime is 21905173. The next prime is 21905203. The reversal of 21905195 is 59150912.

It is a cyclic number.

It is not a de Polignac number, because 21905195 - 2¹⁶ = 21839659 is a prime.

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, 7634 + ... + 10103.

It is an arithmetic number, because the mean of its divisors is an integer number (1862490).

Almost surely, 2^21905195 is an apocalyptic number.

21905195 is a deficient number, since it is larger than the sum of its proper divisors (7894645).

21905195 is a wasteful number, since it uses less digits than its factorization.

21905195 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17774.

The product of its (nonzero) digits is 4050, while the sum is 32.

The square root of 21905195 is about 4680.2986015852. The cubic root of 21905195 is about 279.8008575485.

The spelling of 21905195 in words is "twenty-one million, nine hundred five thousand, one hundred ninety-five".