1720818849 has 32 divisors (see below), whose sum is σ = 2480670720. Its totient is φ = 1058766912.

The previous prime is 1720818817. The next prime is 1720818857. The reversal of 1720818849 is 9488180271.

It is not a de Polignac number, because 1720818849 - 2⁵ = 1720818817 is a prime.

It is a super-3 number, since 3×1720818849³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1720818798 and 1720818807.

It is not an unprimeable number, because it can be changed into a prime (1720818859) 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, 170934 + ... + 180720.

It is an arithmetic number, because the mean of its divisors is an integer number (77520960).

Almost surely, 2^1720818849 is an apocalyptic number.

It is an amenable number.

1720818849 is a deficient number, since it is larger than the sum of its proper divisors (759851871).

1720818849 is a wasteful number, since it uses less digits than its factorization.

1720818849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9909.

The product of its (nonzero) digits is 258048, while the sum is 48.

The square root of 1720818849 is about 41482.7536332872. The cubic root of 1720818849 is about 1198.3353884859.

The spelling of 1720818849 in words is "one billion, seven hundred twenty million, eight hundred eighteen thousand, eight hundred forty-nine".