21422805 has 16 divisors (see below), whose sum is σ = 36293184. Its totient is φ = 10753280.

The previous prime is 21422803. The next prime is 21422813. The reversal of 21422805 is 50822412.

It is not a de Polignac number, because 21422805 - 2¹ = 21422803 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21422801) 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 in 15 ways as a sum of consecutive naturals, for example, 41751 + ... + 42260.

It is an arithmetic number, because the mean of its divisors is an integer number (2268324).

Almost surely, 2^21422805 is an apocalyptic number.

It is an amenable number.

21422805 is a deficient number, since it is larger than the sum of its proper divisors (14870379).

21422805 is a wasteful number, since it uses less digits than its factorization.

21422805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84036.

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 21422805 is about 4628.4776114831. The cubic root of 21422805 is about 277.7316951406.

The spelling of 21422805 in words is "twenty-one million, four hundred twenty-two thousand, eight hundred five".