17121220 has 12 divisors (see below), whose sum is σ = 35954604. Its totient is φ = 6848480.

The previous prime is 17121211. The next prime is 17121229. The reversal of 17121220 is 2212171.

It is an interprime number because it is at equal distance from previous prime (17121211) and next prime (17121229).

It can be written as a sum of positive squares in 2 ways, for example, as 4955076 + 12166144 = 2226^2 + 3488^2 .

It is a junction number, because it is equal to n+sod(n) for n = 17121194 and 17121203.

It is not an unprimeable number, because it can be changed into a prime (17121229) 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, 428011 + ... + 428050.

It is an arithmetic number, because the mean of its divisors is an integer number (2996217).

Almost surely, 2^17121220 is an apocalyptic number.

17121220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

17121220 is an abundant number, since it is smaller than the sum of its proper divisors (18833384).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

17121220 is a wasteful number, since it uses less digits than its factorization.

17121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 856070 (or 856068 counting only the distinct ones).

The product of its (nonzero) digits is 56, while the sum is 16.

The square root of 17121220 is about 4137.7795978036. The cubic root of 17121220 is about 257.7378704957.

Adding to 17121220 its reverse (2212171), we get a palindrome (19333391).

The spelling of 17121220 in words is "seventeen million, one hundred twenty-one thousand, two hundred twenty".