5661719821961 has 6 divisors (see below), whose sum is σ = 6586082241930. Its totient is φ = 4852902704496.

The previous prime is 5661719821921. The next prime is 5661719821963. The reversal of 5661719821961 is 1691289171665.

It can be written as a sum of positive squares in only one way, i.e., 3942130830400 + 1719588991561 = 1985480^2 + 1311331^2 .

It is not a de Polignac number, because 5661719821961 - 2¹⁸ = 5661719559817 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 5661719821894 and 5661719821903.

It is not an unprimeable number, because it can be changed into a prime (5661719821963) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 57772651196 + ... + 57772651293.

It is an arithmetic number, because the mean of its divisors is an integer number (1097680373655).

Almost surely, 2^{5661719821961} is an apocalyptic number.

It is an amenable number.

5661719821961 is a deficient number, since it is larger than the sum of its proper divisors (924362419969).

5661719821961 is a wasteful number, since it uses less digits than its factorization.

5661719821961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115545302503 (or 115545302496 counting only the distinct ones).

The product of its digits is 9797760, while the sum is 62.

The spelling of 5661719821961 in words is "five trillion, six hundred sixty-one billion, seven hundred nineteen million, eight hundred twenty-one thousand, nine hundred sixty-one".