1780720640671 has 16 divisors (see below), whose sum is σ = 2090933006400. Its totient is φ = 1484496599040.

The previous prime is 1780720640659. The next prime is 1780720640687. The reversal of 1780720640671 is 1760460270871.

It is not a de Polignac number, because 1780720640671 - 2¹⁵ = 1780720607903 is a prime.

It is a super-2 number, since 2×1780720640671² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1780720640651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 688450 + ... + 2008831.

It is an arithmetic number, because the mean of its divisors is an integer number (130683312900).

Almost surely, 2^{1780720640671} is an apocalyptic number.

1780720640671 is a deficient number, since it is larger than the sum of its proper divisors (310212365729).

1780720640671 is a wasteful number, since it uses less digits than its factorization.

1780720640671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2699874.

The product of its (nonzero) digits is 790272, while the sum is 49.

The spelling of 1780720640671 in words is "one trillion, seven hundred eighty billion, seven hundred twenty million, six hundred forty thousand, six hundred seventy-one".