21105006 has 16 divisors (see below), whose sum is σ = 45457104. Its totient is φ = 6493824.

The previous prime is 21104999. The next prime is 21105013. The reversal of 21105006 is 60050112.

It is an interprime number because it is at equal distance from previous prime (21104999) and next prime (21105013).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 135211 + ... + 135366.

It is an arithmetic number, because the mean of its divisors is an integer number (2841069).

Almost surely, 2^21105006 is an apocalyptic number.

21105006 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21105006 is an abundant number, since it is smaller than the sum of its proper divisors (24352098).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21105006 is a wasteful number, since it uses less digits than its factorization.

21105006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270595.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 21105006 is about 4594.0185023572. The cubic root of 21105006 is about 276.3515002763.

Adding to 21105006 its reverse (60050112), we get a palindrome (81155118).

The spelling of 21105006 in words is "twenty-one million, one hundred five thousand, six".