21204607 has 2 divisors, whose sum is σ = 21204608. Its totient is φ = 21204606.

The previous prime is 21204587. The next prime is 21204619. The reversal of 21204607 is 70640212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21204607 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 (21204107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10602303 + 10602304.

It is an arithmetic number, because the mean of its divisors is an integer number (10602304).

Almost surely, 2^21204607 is an apocalyptic number.

21204607 is a deficient number, since it is larger than the sum of its proper divisors (1).

21204607 is an equidigital number, since it uses as much as digits as its factorization.

21204607 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 21204607 is about 4604.8460343425. The cubic root of 21204607 is about 276.7855473690.

Adding to 21204607 its reverse (70640212), we get a palindrome (91844819).

The spelling of 21204607 in words is "twenty-one million, two hundred four thousand, six hundred seven".