21973705 has 16 divisors (see below), whose sum is σ = 28514304. Its totient is φ = 16159680.

The previous prime is 21973697. The next prime is 21973729. The reversal of 21973705 is 50737912.

It is not a de Polignac number, because 21973705 - 2³ = 21973697 is a prime.

It is a super-2 number, since 2×21973705² = 965687422854050, which contains 22 as substring.

It is an unprimeable number.

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, 19672 + ... + 20758.

It is an arithmetic number, because the mean of its divisors is an integer number (1782144).

Almost surely, 2^21973705 is an apocalyptic number.

It is an amenable number.

21973705 is a deficient number, since it is larger than the sum of its proper divisors (6540599).

21973705 is a wasteful number, since it uses less digits than its factorization.

21973705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1416.

The product of its (nonzero) digits is 13230, while the sum is 34.

The square root of 21973705 is about 4687.6118653319. The cubic root of 21973705 is about 280.0922527650.

The spelling of 21973705 in words is "twenty-one million, nine hundred seventy-three thousand, seven hundred five".