21064417 has 4 divisors (see below), whose sum is σ = 22979376. Its totient is φ = 19149460.

The previous prime is 21064363. The next prime is 21064471. The reversal of 21064417 is 71446012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (21064363) and next prime (21064471).

It is not a de Polignac number, because 21064417 - 2¹¹ = 21062369 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21064391 and 21064400.

It is not an unprimeable number, because it can be changed into a prime (21064117) 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 in 3 ways as a sum of consecutive naturals, for example, 957463 + ... + 957484.

It is an arithmetic number, because the mean of its divisors is an integer number (5744844).

Almost surely, 2^21064417 is an apocalyptic number.

It is an amenable number.

21064417 is a deficient number, since it is larger than the sum of its proper divisors (1914959).

21064417 is a wasteful number, since it uses less digits than its factorization.

21064417 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1914958.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 21064417 is about 4589.5987842076. The cubic root of 21064417 is about 276.1742274933.

The spelling of 21064417 in words is "twenty-one million, sixty-four thousand, four hundred seventeen".