1720640013457 has 4 divisors (see below), whose sum is σ = 1722715575220. Its totient is φ = 1718564451696.

The previous prime is 1720640013431. The next prime is 1720640013467. The reversal of 1720640013457 is 7543100460271.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 824520296961 + 896119716496 = 908031^2 + 946636^2 .

It is a cyclic number.

It is not a de Polignac number, because 1720640013457 - 2²³ = 1720631624849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1720640013467) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1037779638 + ... + 1037781295.

It is an arithmetic number, because the mean of its divisors is an integer number (430678893805).

Almost surely, 2^{1720640013457} is an apocalyptic number.

It is an amenable number.

1720640013457 is a deficient number, since it is larger than the sum of its proper divisors (2075561763).

1720640013457 is an equidigital number, since it uses as much as digits as its factorization.

1720640013457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2075561762.

The product of its (nonzero) digits is 141120, while the sum is 40.

The spelling of 1720640013457 in words is "one trillion, seven hundred twenty billion, six hundred forty million, thirteen thousand, four hundred fifty-seven".