21021067 has 2 divisors, whose sum is σ = 21021068. Its totient is φ = 21021066.

The previous prime is 21021053. The next prime is 21021083. The reversal of 21021067 is 76012012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21021067 - 2¹⁵ = 20988299 is a prime.

It is not a weakly prime, because it can be changed into another prime (21021047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510533 + 10510534.

It is an arithmetic number, because the mean of its divisors is an integer number (10510534).

Almost surely, 2^21021067 is an apocalyptic number.

21021067 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021067 is an equidigital number, since it uses as much as digits as its factorization.

21021067 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 168, while the sum is 19.

The square root of 21021067 is about 4584.8737169087. The cubic root of 21021067 is about 275.9846443533.

Adding to 21021067 its reverse (76012012), we get a palindrome (97033079).

The spelling of 21021067 in words is "twenty-one million, twenty-one thousand, sixty-seven".