21966069 has 4 divisors (see below), whose sum is σ = 29288096. Its totient is φ = 14644044.

The previous prime is 21966067. The next prime is 21966097. The reversal of 21966069 is 96066912.

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 not a de Polignac number, because 21966069 - 2¹ = 21966067 is a prime.

It is a super-2 number, since 2×21966069² = 965016374625522, 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 (21966067) 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, 3661009 + ... + 3661014.

It is an arithmetic number, because the mean of its divisors is an integer number (7322024).

Almost surely, 2^21966069 is an apocalyptic number.

It is an amenable number.

21966069 is a deficient number, since it is larger than the sum of its proper divisors (7322027).

21966069 is an equidigital number, since it uses as much as digits as its factorization.

21966069 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7322026.

The product of its (nonzero) digits is 34992, while the sum is 39.

The square root of 21966069 is about 4686.7973073305. The cubic root of 21966069 is about 280.0598044025.

The spelling of 21966069 in words is "twenty-one million, nine hundred sixty-six thousand, sixty-nine".