778419762961 has 9 divisors (see below), whose sum is σ = 781688117361. Its totient is φ = 775165028352.

The previous prime is 778419762947. The next prime is 778419762977. The reversal of 778419762961 is 169267914877.

The square root of 778419762961 is 882281.

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 171204785361 + 607214977600 = 413769^2 + 779240^2 .

It is not a de Polignac number, because 778419762961 - 2⁵ = 778419762929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (778416762961) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 226744501 + ... + 226747933.

Almost surely, 2^778419762961 is an apocalyptic number.

778419762961 is the 882281-st square number.

778419762961 is the 441141-st centered octagonal number.

It is an amenable number.

778419762961 is a deficient number, since it is larger than the sum of its proper divisors (3268354400).

778419762961 is an frugal number, since it uses more digits than its factorization.

778419762961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7380 (or 3690 counting only the distinct ones).

The product of its digits is 64012032, while the sum is 67.

The spelling of 778419762961 in words is "seven hundred seventy-eight billion, four hundred nineteen million, seven hundred sixty-two thousand, nine hundred sixty-one".