21982305 has 8 divisors (see below), whose sum is σ = 35171712. Its totient is φ = 11723888.

The previous prime is 21982277. The next prime is 21982313. The reversal of 21982305 is 50328912.

It is a happy number.

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 21982305 - 2⁹ = 21981793 is a prime.

It is a super-2 number, since 2×21982305² = 966443466226050, which contains 22 as substring.

It is a Curzon number.

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 7 ways as a sum of consecutive naturals, for example, 732729 + ... + 732758.

It is an arithmetic number, because the mean of its divisors is an integer number (4396464).

Almost surely, 2^21982305 is an apocalyptic number.

It is an amenable number.

21982305 is a deficient number, since it is larger than the sum of its proper divisors (13189407).

21982305 is a wasteful number, since it uses less digits than its factorization.

21982305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1465495.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 21982305 is about 4688.5290870379. The cubic root of 21982305 is about 280.1287885426.

The spelling of 21982305 in words is "twenty-one million, nine hundred eighty-two thousand, three hundred five".