21001319 has 2 divisors, whose sum is σ = 21001320.
Its totient is φ = 21001318.
The previous prime is 21001247. The next prime is 21001349. The reversal of 21001319 is 91310012.
It is a happy number.
It is a strong prime.
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-21001319 is a prime.
It is a super-2 number, since 2×210013192 = 882110799479522, which contains 22 as substring.
It is a junction number, because it is equal to n+sod(n) for n = 21001297 and 21001306.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (21001349) 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, 10500659 + 10500660.
It is an arithmetic number, because the mean of its divisors is an integer number (10500660).
Almost surely, 221001319 is an apocalyptic number.
21001319 is a deficient number, since it is larger than the sum of its proper divisors (1).
21001319 is an equidigital number, since it uses as much as digits as its factorization.
21001319 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 54, while the sum is 17.
The square root of 21001319 is about 4582.7196073947.
The cubic root of 21001319 is about 275.8981937410.
The spelling of 21001319 in words is "twenty-one million, one thousand, three hundred nineteen".