21022305 has 8 divisors (see below), whose sum is σ = 33635712. Its totient is φ = 11211888.

The previous prime is 21022279. The next prime is 21022357. The reversal of 21022305 is 50322012.

21022305 is nontrivially palindromic in base 7.

21022305 is an esthetic number in base 7, because in such base its adjacent digits differ by 1.

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

It is not a de Polignac number, because 21022305 - 2⁸ = 21022049 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15), and also a Moran number because the ratio is a prime number: 1401487 = 21022305 / (2 + 1 + 0 + 2 + 2 + 3 + 0 + 5).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 700729 + ... + 700758.

It is an arithmetic number, because the mean of its divisors is an integer number (4204464).

Almost surely, 2^21022305 is an apocalyptic number.

It is an amenable number.

21022305 is a deficient number, since it is larger than the sum of its proper divisors (12613407).

21022305 is a wasteful number, since it uses less digits than its factorization.

21022305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1401495.

The product of its (nonzero) digits is 120, while the sum is 15.

The square root of 21022305 is about 4585.0087240920. The cubic root of 21022305 is about 275.9900621290.

Adding to 21022305 its reverse (50322012), we get a palindrome (71344317).

The spelling of 21022305 in words is "twenty-one million, twenty-two thousand, three hundred five".