21804007 has 2 divisors, whose sum is σ = 21804008. Its totient is φ = 21804006.

The previous prime is 21803983. The next prime is 21804037. The reversal of 21804007 is 70040812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21804007 - 2⁷ = 21803879 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21804037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10902003 + 10902004.

It is an arithmetic number, because the mean of its divisors is an integer number (10902004).

Almost surely, 2^21804007 is an apocalyptic number.

21804007 is a deficient number, since it is larger than the sum of its proper divisors (1).

21804007 is an equidigital number, since it uses as much as digits as its factorization.

21804007 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 21804007 is about 4669.4760948098. The cubic root of 21804007 is about 279.3693587405.

Adding to 21804007 its reverse (70040812), we get a palindrome (91844819).

The spelling of 21804007 in words is "twenty-one million, eight hundred four thousand, seven".