1961716775769 has 81 divisors (see below), whose sum is σ = 3120747870877. Its totient is φ = 1187181988608.

The previous prime is 1961716775719. The next prime is 1961716775779. The reversal of 1961716775769 is 9675776171691.

The square root of 1961716775769 is 1400613.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 193912526025 + 1767804249744 = 440355^2 + 1329588^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1961716775769 is a prime.

It is a super-2 number, since 2×1961716775769² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1961716775697 and 1961716775706.

It is not an unprimeable number, because it can be changed into a prime (1961716775719) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 2071506154 + ... + 2071507100.

Almost surely, 2^{1961716775769} is an apocalyptic number.

1961716775769 is the 1400613-rd square number.

1961716775769 is the 700307-th centered octagonal number.

It is an amenable number.

1961716775769 is a deficient number, since it is larger than the sum of its proper divisors (1159031095108).

1961716775769 is an frugal number, since it uses more digits than its factorization.

1961716775769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1992 (or 996 counting only the distinct ones).

The product of its digits is 210039480, while the sum is 72.

The spelling of 1961716775769 in words is "one trillion, nine hundred sixty-one billion, seven hundred sixteen million, seven hundred seventy-five thousand, seven hundred sixty-nine".