21700211 has 16 divisors (see below), whose sum is σ = 24948000. Its totient is φ = 18697728.

The previous prime is 21700187. The next prime is 21700219. The reversal of 21700211 is 11200712.

It is a cyclic number.

It is not a de Polignac number, because 21700211 - 2¹⁰ = 21699187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21700219) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32600 + ... + 33258.

It is an arithmetic number, because the mean of its divisors is an integer number (1559250).

Almost surely, 2^21700211 is an apocalyptic number.

21700211 is a deficient number, since it is larger than the sum of its proper divisors (3247789).

21700211 is a wasteful number, since it uses less digits than its factorization.

21700211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 838.

The product of its (nonzero) digits is 28, while the sum is 14.

The square root of 21700211 is about 4658.3485271070. The cubic root of 21700211 is about 278.9253492634.

Adding to 21700211 its reverse (11200712), we get a palindrome (32900923).

The spelling of 21700211 in words is "twenty-one million, seven hundred thousand, two hundred eleven".