21067069 has 4 divisors (see below), whose sum is σ = 21083040. Its totient is φ = 21051100.

The previous prime is 21067043. The next prime is 21067087. The reversal of 21067069 is 96076012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21067069 - 2⁵ = 21067037 is a prime.

It is a super-2 number, since 2×21067069² = 887642792501522, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21067069.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21067019) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 5809 + ... + 8710.

It is an arithmetic number, because the mean of its divisors is an integer number (5270760).

Almost surely, 2^21067069 is an apocalyptic number.

It is an amenable number.

21067069 is a deficient number, since it is larger than the sum of its proper divisors (15971).

21067069 is a wasteful number, since it uses less digits than its factorization.

21067069 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15970.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 21067069 is about 4589.8876892578. The cubic root of 21067069 is about 276.1858170745.

The spelling of 21067069 in words is "twenty-one million, sixty-seven thousand, sixty-nine".