1961601570865 has 4 divisors (see below), whose sum is σ = 2353921885044. Its totient is φ = 1569281256688.

The previous prime is 1961601570839. The next prime is 1961601570871. The reversal of 1961601570865 is 5680751061691.

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 1146132971776 + 815468599089 = 1070576^2 + 903033^2 .

It is a cyclic number.

It is not a de Polignac number, because 1961601570865 - 2¹⁹ = 1961601046577 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 196160157082 + ... + 196160157091.

It is an arithmetic number, because the mean of its divisors is an integer number (588480471261).

Almost surely, 2^{1961601570865} is an apocalyptic number.

It is an amenable number.

1961601570865 is a deficient number, since it is larger than the sum of its proper divisors (392320314179).

1961601570865 is an equidigital number, since it uses as much as digits as its factorization.

1961601570865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 392320314178.

The product of its (nonzero) digits is 2721600, while the sum is 55.

The spelling of 1961601570865 in words is "one trillion, nine hundred sixty-one billion, six hundred one million, five hundred seventy thousand, eight hundred sixty-five".