21385869 has 8 divisors (see below), whose sum is σ = 28536000. Its totient is φ = 14246496.

The previous prime is 21385867. The next prime is 21385879. The reversal of 21385869 is 96858312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21385869 - 2¹ = 21385867 is a prime.

It is a super-2 number, since 2×21385869² = 914710785770322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21385869.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21385867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5632 + ... + 8630.

It is an arithmetic number, because the mean of its divisors is an integer number (3567000).

Almost surely, 2^21385869 is an apocalyptic number.

It is an amenable number.

21385869 is a deficient number, since it is larger than the sum of its proper divisors (7150131).

21385869 is a wasteful number, since it uses less digits than its factorization.

21385869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5379.

The product of its digits is 103680, while the sum is 42.

The square root of 21385869 is about 4624.4858092549. The cubic root of 21385869 is about 277.5719868432.

The spelling of 21385869 in words is "twenty-one million, three hundred eighty-five thousand, eight hundred sixty-nine".