21700505 has 8 divisors (see below), whose sum is σ = 26073792. Its totient is φ = 17338288.

The previous prime is 21700501. The next prime is 21700513. The reversal of 21700505 is 50500712.

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 21700505 - 2² = 21700501 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21700501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2444 + ... + 7026.

It is an arithmetic number, because the mean of its divisors is an integer number (3259224).

Almost surely, 2^21700505 is an apocalyptic number.

It is an amenable number.

21700505 is a deficient number, since it is larger than the sum of its proper divisors (4373287).

21700505 is an equidigital number, since it uses as much as digits as its factorization.

21700505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5535.

The product of its (nonzero) digits is 350, while the sum is 20.

The square root of 21700505 is about 4658.3800832478. The cubic root of 21700505 is about 278.9266089083.

The spelling of 21700505 in words is "twenty-one million, seven hundred thousand, five hundred five".