20810217 has 4 divisors (see below), whose sum is σ = 27746960. Its totient is φ = 13873476.

The previous prime is 20810203. The next prime is 20810219. The reversal of 20810217 is 71201802.

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 not a de Polignac number, because 20810217 - 2⁸ = 20809961 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20810193 and 20810202.

It is not an unprimeable number, because it can be changed into a prime (20810219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3468367 + ... + 3468372.

It is an arithmetic number, because the mean of its divisors is an integer number (6936740).

Almost surely, 2^20810217 is an apocalyptic number.

It is an amenable number.

20810217 is a deficient number, since it is larger than the sum of its proper divisors (6936743).

20810217 is an equidigital number, since it uses as much as digits as its factorization.

20810217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6936742.

The product of its (nonzero) digits is 224, while the sum is 21.

The square root of 20810217 is about 4561.8216756029. The cubic root of 20810217 is about 275.0587951422.

The spelling of 20810217 in words is "twenty million, eight hundred ten thousand, two hundred seventeen".