21199669 has 4 divisors (see below), whose sum is σ = 21306400. Its totient is φ = 21092940.

The previous prime is 21199643. The next prime is 21199681. The reversal of 21199669 is 96699112.

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 21199669 - 2¹¹ = 21197621 is a prime.

It is a super-2 number, since 2×21199669² = 898851931419122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21199639) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53067 + ... + 53464.

It is an arithmetic number, because the mean of its divisors is an integer number (5326600).

Almost surely, 2^21199669 is an apocalyptic number.

It is an amenable number.

21199669 is a deficient number, since it is larger than the sum of its proper divisors (106731).

21199669 is a wasteful number, since it uses less digits than its factorization.

21199669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106730.

The product of its digits is 52488, while the sum is 43.

The square root of 21199669 is about 4604.3098288451. The cubic root of 21199669 is about 276.7640603223.

The spelling of 21199669 in words is "twenty-one million, one hundred ninety-nine thousand, six hundred sixty-nine".