1708421296721 has 4 divisors (see below), whose sum is σ = 1708462456500. Its totient is φ = 1708380136944.

The previous prime is 1708421296709. The next prime is 1708421296727. The reversal of 1708421296721 is 1276921248071.

It is a happy number.

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 212963790400 + 1495457506321 = 461480^2 + 1222889^2 .

It is a cyclic number.

It is not a de Polignac number, because 1708421296721 - 2⁶ = 1708421296657 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1708421296721.

It is not an unprimeable number, because it can be changed into a prime (1708421296727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20517566 + ... + 20600663.

It is an arithmetic number, because the mean of its divisors is an integer number (427115614125).

Almost surely, 2^{1708421296721} is an apocalyptic number.

It is an amenable number.

1708421296721 is a deficient number, since it is larger than the sum of its proper divisors (41159779).

1708421296721 is an equidigital number, since it uses as much as digits as its factorization.

1708421296721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41159778.

The product of its (nonzero) digits is 677376, while the sum is 50.

The spelling of 1708421296721 in words is "one trillion, seven hundred eight billion, four hundred twenty-one million, two hundred ninety-six thousand, seven hundred twenty-one".