21065319 has 32 divisors (see below), whose sum is σ = 35846400. Its totient is φ = 12091680.

The previous prime is 21065287. The next prime is 21065333. The reversal of 21065319 is 91356012.

21065319 is a `hidden beast` number, since 2 + 1 + 0 + 653 + 1 + 9 = 666.

It is not a de Polignac number, because 21065319 - 2⁵ = 21065287 is a prime.

It is a super-2 number, since 2×21065319² = 887495329143522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 21065292 and 21065301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21065819) 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 in 31 ways as a sum of consecutive naturals, for example, 3777 + ... + 7509.

It is an arithmetic number, because the mean of its divisors is an integer number (1120200).

Almost surely, 2^21065319 is an apocalyptic number.

21065319 is a deficient number, since it is larger than the sum of its proper divisors (14781081).

21065319 is a wasteful number, since it uses less digits than its factorization.

21065319 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3772 (or 3766 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 21065319 is about 4589.6970488258. The cubic root of 21065319 is about 276.1781694585.

The spelling of 21065319 in words is "twenty-one million, sixty-five thousand, three hundred nineteen".