21885006 has 64 divisors (see below), whose sum is σ = 53706240. Its totient is φ = 5850240.

The previous prime is 21884987. The next prime is 21885013. The reversal of 21885006 is 60058812.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19180 + ... + 20288.

It is an arithmetic number, because the mean of its divisors is an integer number (839160).

Almost surely, 2^21885006 is an apocalyptic number.

21885006 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21885006, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26853120).

21885006 is an abundant number, since it is smaller than the sum of its proper divisors (31821234).

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

21885006 is a wasteful number, since it uses less digits than its factorization.

21885006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1161.

The product of its (nonzero) digits is 3840, while the sum is 30.

The square root of 21885006 is about 4678.1412975668. The cubic root of 21885006 is about 279.7148713119.

The spelling of 21885006 in words is "twenty-one million, eight hundred eighty-five thousand, six".