1961318386945 has 32 divisors (see below), whose sum is σ = 2384962165152. Its totient is φ = 1548236685312.

The previous prime is 1961318386919. The next prime is 1961318386969. The reversal of 1961318386945 is 5496838131691.

It can be written as a sum of positive squares in 16 ways, for example, as 1467557799184 + 493760587761 = 1211428^2 + 702681^2 .

It is a cyclic number.

It is not a de Polignac number, because 1961318386945 - 2²⁵ = 1961284832513 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 481539429 + ... + 481543501.

It is an arithmetic number, because the mean of its divisors is an integer number (74530067661).

Almost surely, 2^{1961318386945} is an apocalyptic number.

It is an amenable number.

1961318386945 is a deficient number, since it is larger than the sum of its proper divisors (423643778207).

1961318386945 is a wasteful number, since it uses less digits than its factorization.

1961318386945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6901.

The product of its digits is 33592320, while the sum is 64.

The spelling of 1961318386945 in words is "one trillion, nine hundred sixty-one billion, three hundred eighteen million, three hundred eighty-six thousand, nine hundred forty-five".