21713842444661 has 4 divisors (see below), whose sum is σ = 21720694401900. Its totient is φ = 21706990487424.

The previous prime is 21713842444643. The next prime is 21713842444667. The reversal of 21713842444661 is 16644424831712.

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 7151078222500 + 14562764222161 = 2674150^2 + 3816119^2 .

It is a cyclic number.

It is not a de Polignac number, because 21713842444661 - 2¹⁴ = 21713842428277 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 (21713842444667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3425973866 + ... + 3425980203.

It is an arithmetic number, because the mean of its divisors is an integer number (5430173600475).

Almost surely, 2^{21713842444661} is an apocalyptic number.

It is an amenable number.

21713842444661 is a deficient number, since it is larger than the sum of its proper divisors (6851957239).

21713842444661 is an equidigital number, since it uses as much as digits as its factorization.

21713842444661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6851957238.

The product of its digits is 6193152, while the sum is 53.

The spelling of 21713842444661 in words is "twenty-one trillion, seven hundred thirteen billion, eight hundred forty-two million, four hundred forty-four thousand, six hundred sixty-one".