17121920121 has 12 divisors (see below), whose sum is σ = 24950528148. Its totient is φ = 11313598464.

The previous prime is 17121920113. The next prime is 17121920143. The reversal of 17121920121 is 12102912171.

It can be written as a sum of positive squares in 2 ways, for example, as 237776400 + 16884143721 = 15420^2 + 129939^2 .

It is not a de Polignac number, because 17121920121 - 2³ = 17121920113 is a prime.

It is not an unprimeable number, because it can be changed into a prime (17121920021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8416840 + ... + 8418873.

It is an arithmetic number, because the mean of its divisors is an integer number (2079210679).

Almost surely, 2^17121920121 is an apocalyptic number.

It is an amenable number.

17121920121 is a deficient number, since it is larger than the sum of its proper divisors (7828608027).

17121920121 is a wasteful number, since it uses less digits than its factorization.

17121920121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16835832 (or 16835829 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 27.

The spelling of 17121920121 in words is "seventeen billion, one hundred twenty-one million, nine hundred twenty thousand, one hundred twenty-one".