21350217 has 32 divisors (see below), whose sum is σ = 33755904. Its totient is φ = 11750400.

The previous prime is 21350213. The next prime is 21350291. The reversal of 21350217 is 71205312.

It is not a de Polignac number, because 21350217 - 2² = 21350213 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 21350193 and 21350202.

It is not an unprimeable number, because it can be changed into a prime (21350213) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 117867 + ... + 118047.

It is an arithmetic number, because the mean of its divisors is an integer number (1054872).

Almost surely, 2^21350217 is an apocalyptic number.

It is an amenable number.

21350217 is a deficient number, since it is larger than the sum of its proper divisors (12405687).

21350217 is a wasteful number, since it uses less digits than its factorization.

21350217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 21350217 is about 4620.6295025678. The cubic root of 21350217 is about 277.4176559511.

Adding to 21350217 its reverse (71205312), we get a palindrome (92555529).

The spelling of 21350217 in words is "twenty-one million, three hundred fifty thousand, two hundred seventeen".