21111706 has 16 divisors (see below), whose sum is σ = 39481920. Its totient is φ = 8225280.

The previous prime is 21111703. The next prime is 21111743. The reversal of 21111706 is 60711112.

It is not an unprimeable number, because it can be changed into a prime (21111703) 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, 68391 + ... + 68698.

It is an arithmetic number, because the mean of its divisors is an integer number (2467620).

Almost surely, 2^21111706 is an apocalyptic number.

21111706 is a deficient number, since it is larger than the sum of its proper divisors (18370214).

21111706 is a wasteful number, since it uses less digits than its factorization.

21111706 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137109.

The product of its (nonzero) digits is 84, while the sum is 19.

The square root of 21111706 is about 4594.7476535714. The cubic root of 21111706 is about 276.3807407190.

Adding to 21111706 its reverse (60711112), we get a palindrome (81822818).

The spelling of 21111706 in words is "twenty-one million, one hundred eleven thousand, seven hundred six".