1720487865 has 16 divisors (see below), whose sum is σ = 2761754688. Its totient is φ = 914602176.

The previous prime is 1720487863. The next prime is 1720487887. The reversal of 1720487865 is 5687840271.

It is not a de Polignac number, because 1720487865 - 2¹ = 1720487863 is a prime.

It is a super-2 number, since 2×1720487865² = 5920156987224516450, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1720487863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 182202 + ... + 191411.

It is an arithmetic number, because the mean of its divisors is an integer number (172609668).

Almost surely, 2^1720487865 is an apocalyptic number.

1720487865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1720487865 is a deficient number, since it is larger than the sum of its proper divisors (1041266823).

1720487865 is a wasteful number, since it uses less digits than its factorization.

1720487865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373928.

The product of its (nonzero) digits is 752640, while the sum is 48.

The square root of 1720487865 is about 41478.7640244981. The cubic root of 1720487865 is about 1198.2585538881.

The spelling of 1720487865 in words is "one billion, seven hundred twenty million, four hundred eighty-seven thousand, eight hundred sixty-five".