21011006 has 16 divisors (see below), whose sum is σ = 33342624. Its totient is φ = 9909504.

The previous prime is 21010987. The next prime is 21011009. The reversal of 21011006 is 60011012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 230 + ... + 6486.

It is an arithmetic number, because the mean of its divisors is an integer number (2083914).

Almost surely, 2^21011006 is an apocalyptic number.

21011006 is a deficient number, since it is larger than the sum of its proper divisors (12331618).

21011006 is a wasteful number, since it uses less digits than its factorization.

21011006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6355.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 21011006 is about 4583.7763907067. The cubic root of 21011006 is about 275.9406071879.

Adding to 21011006 its reverse (60011012), we get a palindrome (81022018).

The spelling of 21011006 in words is "twenty-one million, eleven thousand, six".