21100006 has 4 divisors (see below), whose sum is σ = 31650012. Its totient is φ = 10550002.

The previous prime is 21100003. The next prime is 21100007. The reversal of 21100006 is 60000112.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 21099965 and 21100001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5275000 + ... + 5275003.

It is an arithmetic number, because the mean of its divisors is an integer number (7912503).

Almost surely, 2^21100006 is an apocalyptic number.

21100006 is a deficient number, since it is larger than the sum of its proper divisors (10550006).

21100006 is a wasteful number, since it uses less digits than its factorization.

21100006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10550005.

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 21100006 is about 4593.4742842428. The cubic root of 21100006 is about 276.3296750178.

Adding to 21100006 its reverse (60000112), we get a palindrome (81100118).

The spelling of 21100006 in words is "twenty-one million, one hundred thousand, six".