21827091 has 32 divisors (see below), whose sum is σ = 34659072. Its totient is φ = 12044160.

The previous prime is 21827083. The next prime is 21827093. The reversal of 21827091 is 19072812.

It is not a de Polignac number, because 21827091 - 2³ = 21827083 is a prime.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (21827093) 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 31 ways as a sum of consecutive naturals, for example, 35301 + ... + 35913.

It is an arithmetic number, because the mean of its divisors is an integer number (1083096).

Almost surely, 2^21827091 is an apocalyptic number.

21827091 is a deficient number, since it is larger than the sum of its proper divisors (12831981).

21827091 is a wasteful number, since it uses less digits than its factorization.

21827091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 723.

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 21827091 is about 4671.9472385719. The cubic root of 21827091 is about 279.4679138328.

The spelling of 21827091 in words is "twenty-one million, eight hundred twenty-seven thousand, ninety-one".