21343705 has 8 divisors (see below), whose sum is σ = 25735104. Its totient is φ = 16993200.

The previous prime is 21343697. The next prime is 21343723. The reversal of 21343705 is 50734312.

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

It is not a de Polignac number, because 21343705 - 2³ = 21343697 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21343705.

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, 9061 + ... + 11170.

It is an arithmetic number, because the mean of its divisors is an integer number (3216888).

Almost surely, 2^21343705 is an apocalyptic number.

It is an amenable number.

21343705 is a deficient number, since it is larger than the sum of its proper divisors (4391399).

21343705 is a wasteful number, since it uses less digits than its factorization.

21343705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20447.

The product of its (nonzero) digits is 2520, while the sum is 25.

The square root of 21343705 is about 4619.9247829375. The cubic root of 21343705 is about 277.3894481585.

The spelling of 21343705 in words is "twenty-one million, three hundred forty-three thousand, seven hundred five".