21807069 has 4 divisors (see below), whose sum is σ = 29076096. Its totient is φ = 14538044.

The previous prime is 21807067. The next prime is 21807083. The reversal of 21807069 is 96070812.

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 21807069 - 2¹ = 21807067 is a prime.

It is a super-2 number, since 2×21807069² = 951096516741522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21807067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3634509 + ... + 3634514.

It is an arithmetic number, because the mean of its divisors is an integer number (7269024).

Almost surely, 2^21807069 is an apocalyptic number.

It is an amenable number.

21807069 is a deficient number, since it is larger than the sum of its proper divisors (7269027).

21807069 is an equidigital number, since it uses as much as digits as its factorization.

21807069 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7269026.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 21807069 is about 4669.8039573413. The cubic root of 21807069 is about 279.3824356784.

The spelling of 21807069 in words is "twenty-one million, eight hundred seven thousand, sixty-nine".