21909795 has 8 divisors (see below), whose sum is σ = 35055696. Its totient is φ = 11685216.

The previous prime is 21909743. The next prime is 21909799. The reversal of 21909795 is 59790912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21909795 - 2¹⁰ = 21908771 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21909799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 730312 + ... + 730341.

It is an arithmetic number, because the mean of its divisors is an integer number (4381962).

Almost surely, 2^21909795 is an apocalyptic number.

21909795 is a deficient number, since it is larger than the sum of its proper divisors (13145901).

21909795 is a wasteful number, since it uses less digits than its factorization.

21909795 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1460661.

The product of its (nonzero) digits is 51030, while the sum is 42.

The square root of 21909795 is about 4680.7899974256. The cubic root of 21909795 is about 279.8204418505.

The spelling of 21909795 in words is "twenty-one million, nine hundred nine thousand, seven hundred ninety-five".