21844705 has 8 divisors (see below), whose sum is σ = 26350632. Its totient is φ = 17384448.

The previous prime is 21844703. The next prime is 21844727. The reversal of 21844705 is 50744812.

It can be written as a sum of positive squares in 4 ways, for example, as 91809 + 21752896 = 303^2 + 4664^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21844705 - 2¹ = 21844703 is a prime.

It is a super-2 number, since 2×21844705² = 954382273074050, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21844703) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10354 + ... + 12283.

It is an arithmetic number, because the mean of its divisors is an integer number (3293829).

Almost surely, 2^21844705 is an apocalyptic number.

It is an amenable number.

21844705 is a deficient number, since it is larger than the sum of its proper divisors (4505927).

21844705 is a wasteful number, since it uses less digits than its factorization.

21844705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22835.

The product of its (nonzero) digits is 8960, while the sum is 31.

The square root of 21844705 is about 4673.8319396401. The cubic root of 21844705 is about 279.5430685155.

It can be divided in two parts, 2184 and 4705, that added together give a square (6889 = 83²).

The spelling of 21844705 in words is "twenty-one million, eight hundred forty-four thousand, seven hundred five".