21241705 has 8 divisors (see below), whose sum is σ = 25519104. Its totient is φ = 16974000.

The previous prime is 21241667. The next prime is 21241723. The reversal of 21241705 is 50714212.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-21241705 is a prime.

It is a Duffinian 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, 3910 + ... + 7600.

It is an arithmetic number, because the mean of its divisors is an integer number (3189888).

Almost surely, 2^21241705 is an apocalyptic number.

It is an amenable number.

21241705 is a deficient number, since it is larger than the sum of its proper divisors (4277399).

21241705 is a wasteful number, since it uses less digits than its factorization.

21241705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4847.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 21241705 is about 4608.8724217535. The cubic root of 21241705 is about 276.9468677823.

Adding to 21241705 its reverse (50714212), we get a palindrome (71955917).

The spelling of 21241705 in words is "twenty-one million, two hundred forty-one thousand, seven hundred five".