1721486407681 has 4 divisors (see below), whose sum is σ = 1722312855472. Its totient is φ = 1720659959892.

The previous prime is 1721486407651. The next prime is 1721486407699. The reversal of 1721486407681 is 1867046841271.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1721486407681 - 2¹³ = 1721486399489 is a prime.

It is a super-2 number, since 2×1721486407681² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1721486407621) 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, 413220771 + ... + 413224936.

It is an arithmetic number, because the mean of its divisors is an integer number (430578213868).

Almost surely, 2^{1721486407681} is an apocalyptic number.

It is an amenable number.

1721486407681 is a deficient number, since it is larger than the sum of its proper divisors (826447791).

1721486407681 is an equidigital number, since it uses as much as digits as its factorization.

1721486407681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 826447790.

The product of its (nonzero) digits is 3612672, while the sum is 55.

The spelling of 1721486407681 in words is "one trillion, seven hundred twenty-one billion, four hundred eighty-six million, four hundred seven thousand, six hundred eighty-one".