1961787594961 has 4 divisors (see below), whose sum is σ = 1961794598400. Its totient is φ = 1961780591524.

The previous prime is 1961787594941. The next prime is 1961787594967. The reversal of 1961787594961 is 1694957871691.

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 1961787594961 - 2¹¹ = 1961787592913 is a prime.

It is a super-2 number, since 2×1961787594961² (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 (1961787594967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3063241 + ... + 3647878.

It is an arithmetic number, because the mean of its divisors is an integer number (490448649600).

Almost surely, 2^{1961787594961} is an apocalyptic number.

It is an amenable number.

1961787594961 is a deficient number, since it is larger than the sum of its proper divisors (7003439).

1961787594961 is an equidigital number, since it uses as much as digits as its factorization.

1961787594961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7003438.

The product of its digits is 205752960, while the sum is 73.

The spelling of 1961787594961 in words is "one trillion, nine hundred sixty-one billion, seven hundred eighty-seven million, five hundred ninety-four thousand, nine hundred sixty-one".