21067506 has 48 divisors (see below), whose sum is σ = 48157920. Its totient is φ = 6826680.

The previous prime is 21067499. The next prime is 21067513. The reversal of 21067506 is 60576012.

It is an interprime number because it is at equal distance from previous prime (21067499) and next prime (21067513).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21067506.

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 23 ways as a sum of consecutive naturals, for example, 99741 + ... + 99951.

It is an arithmetic number, because the mean of its divisors is an integer number (1003290).

Almost surely, 2^21067506 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21067506, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24078960).

21067506 is an abundant number, since it is smaller than the sum of its proper divisors (27090414).

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

21067506 is a wasteful number, since it uses less digits than its factorization.

21067506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308 (or 259 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The square root of 21067506 is about 4589.9352936616. The cubic root of 21067506 is about 276.1877267274.

The spelling of 21067506 in words is "twenty-one million, sixty-seven thousand, five hundred six".