1721655212879 has 32 divisors (see below), whose sum is σ = 2096811110400. Its totient is φ = 1410360336000.

The previous prime is 1721655212873. The next prime is 1721655212891. The reversal of 1721655212879 is 9782125561271.

It is not a de Polignac number, because 1721655212879 - 2⁸ = 1721655212623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1721655212873) 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 31 ways as a sum of consecutive naturals, for example, 9383834 + ... + 9565544.

It is an arithmetic number, because the mean of its divisors is an integer number (65525347200).

Almost surely, 2^{1721655212879} is an apocalyptic number.

1721655212879 is a deficient number, since it is larger than the sum of its proper divisors (375155897521).

1721655212879 is a wasteful number, since it uses less digits than its factorization.

1721655212879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182956 (or 182942 counting only the distinct ones).

The product of its digits is 4233600, while the sum is 56.

The spelling of 1721655212879 in words is "one trillion, seven hundred twenty-one billion, six hundred fifty-five million, two hundred twelve thousand, eight hundred seventy-nine".