21963001 has 2 divisors, whose sum is σ = 21963002. Its totient is φ = 21963000.

The previous prime is 21962933. The next prime is 21963017. The reversal of 21963001 is 10036912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15327225 + 6635776 = 3915^2 + 2576^2 .

It is a cyclic number.

It is not a de Polignac number, because 21963001 - 2¹³ = 21954809 is a prime.

It is not a weakly prime, because it can be changed into another prime (21943001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10981500 + 10981501.

It is an arithmetic number, because the mean of its divisors is an integer number (10981501).

Almost surely, 2^21963001 is an apocalyptic number.

It is an amenable number.

21963001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21963001 is an equidigital number, since it uses as much as digits as its factorization.

21963001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 21963001 is about 4686.4699935026. The cubic root of 21963001 is about 280.0467651481.

Adding to 21963001 its reverse (10036912), we get a palindrome (31999913).

The spelling of 21963001 in words is "twenty-one million, nine hundred sixty-three thousand, one".