21845827 has 2 divisors, whose sum is σ = 21845828. Its totient is φ = 21845826.

The previous prime is 21845809. The next prime is 21845843. The reversal of 21845827 is 72854812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21845827 - 2¹⁵ = 21813059 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21845807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10922913 + 10922914.

It is an arithmetic number, because the mean of its divisors is an integer number (10922914).

Almost surely, 2^21845827 is an apocalyptic number.

21845827 is a deficient number, since it is larger than the sum of its proper divisors (1).

21845827 is an equidigital number, since it uses as much as digits as its factorization.

21845827 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35840, while the sum is 37.

The square root of 21845827 is about 4673.9519680887. The cubic root of 21845827 is about 279.5478544495.

The spelling of 21845827 in words is "twenty-one million, eight hundred forty-five thousand, eight hundred twenty-seven".