21063907 has 2 divisors, whose sum is σ = 21063908. Its totient is φ = 21063906.

The previous prime is 21063881. The next prime is 21063983. The reversal of 21063907 is 70936012.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21063907 is a prime.

It is not a weakly prime, because it can be changed into another prime (21063997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10531953 + 10531954.

It is an arithmetic number, because the mean of its divisors is an integer number (10531954).

Almost surely, 2^21063907 is an apocalyptic number.

21063907 is a deficient number, since it is larger than the sum of its proper divisors (1).

21063907 is an equidigital number, since it uses as much as digits as its factorization.

21063907 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2268, while the sum is 28.

The square root of 21063907 is about 4589.5432234592. The cubic root of 21063907 is about 276.1719986162.

Adding to 21063907 its reverse (70936012), we get a palindrome (91999919).

The spelling of 21063907 in words is "twenty-one million, sixty-three thousand, nine hundred seven".