21945005 has 8 divisors (see below), whose sum is σ = 26894592. Its totient is φ = 17182288.

The previous prime is 21944987. The next prime is 21945017. The reversal of 21945005 is 50054912.

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 21945005 - 2⁶ = 21944941 is a prime.

It is a Duffinian number.

It is a congruent number.

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, 46457 + ... + 46926.

It is an arithmetic number, because the mean of its divisors is an integer number (3361824).

Almost surely, 2^21945005 is an apocalyptic number.

It is an amenable number.

21945005 is a deficient number, since it is larger than the sum of its proper divisors (4949587).

21945005 is an equidigital number, since it uses as much as digits as its factorization.

21945005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93435.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 21945005 is about 4684.5496048179. The cubic root of 21945005 is about 279.9702561942.

Adding to 21945005 its reverse (50054912), we get a palindrome (71999917).

The spelling of 21945005 in words is "twenty-one million, nine hundred forty-five thousand, five".