1720288817 has 8 divisors (see below), whose sum is σ = 1852943400. Its totient is φ = 1587680640.

The previous prime is 1720288813. The next prime is 1720288853. The reversal of 1720288817 is 7188820271.

It can be written as a sum of positive squares in 4 ways, for example, as 5997601 + 1714291216 = 2449^2 + 41404^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1720288817 - 2² = 1720288813 is a prime.

It is a super-2 number, since 2×1720288817² = 5918787227790518978, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1720288811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 125309 + ... + 138357.

It is an arithmetic number, because the mean of its divisors is an integer number (231617925).

Almost surely, 2^1720288817 is an apocalyptic number.

It is an amenable number.

1720288817 is a deficient number, since it is larger than the sum of its proper divisors (132654583).

1720288817 is a wasteful number, since it uses less digits than its factorization.

1720288817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23203.

The product of its (nonzero) digits is 100352, while the sum is 44.

The square root of 1720288817 is about 41476.3645586254. The cubic root of 1720288817 is about 1198.2123421571.

The spelling of 1720288817 in words is "one billion, seven hundred twenty million, two hundred eighty-eight thousand, eight hundred seventeen".