21303901 has 2 divisors, whose sum is σ = 21303902. Its totient is φ = 21303900.

The previous prime is 21303857. The next prime is 21303917. The reversal of 21303901 is 10930312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12888100 + 8415801 = 3590^2 + 2901^2 .

It is a cyclic number.

It is not a de Polignac number, because 21303901 - 2¹¹ = 21301853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21303301) 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, 10651950 + 10651951.

It is an arithmetic number, because the mean of its divisors is an integer number (10651951).

Almost surely, 2^21303901 is an apocalyptic number.

It is an amenable number.

21303901 is a deficient number, since it is larger than the sum of its proper divisors (1).

21303901 is an equidigital number, since it uses as much as digits as its factorization.

21303901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 162, while the sum is 19.

The square root of 21303901 is about 4615.6149102801. The cubic root of 21303901 is about 277.2169057888.

The spelling of 21303901 in words is "twenty-one million, three hundred three thousand, nine hundred one".