21041686 has 8 divisors (see below), whose sum is σ = 31596840. Its totient is φ = 10509408.

The previous prime is 21041677. The next prime is 21041707. The reversal of 21041686 is 68614012.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3196 + ... + 7231.

It is an arithmetic number, because the mean of its divisors is an integer number (3949605).

Almost surely, 2^21041686 is an apocalyptic number.

21041686 is a deficient number, since it is larger than the sum of its proper divisors (10555154).

21041686 is a wasteful number, since it uses less digits than its factorization.

21041686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11438.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 21041686 is about 4587.1217555238. The cubic root of 21041686 is about 276.0748501745.

Adding to 21041686 its reverse (68614012), we get a palindrome (89655698).

The spelling of 21041686 in words is "twenty-one million, forty-one thousand, six hundred eighty-six".