2778325582561 has 9 divisors (see below), whose sum is σ = 2782717944979. Its totient is φ = 2773940150200.

The previous prime is 2778325582531. The next prime is 2778325582567. The reversal of 2778325582561 is 1652855238772.

The square root of 2778325582561 is 1666831.

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

It can be written as a sum of positive squares in only one way, i.e., 1829610622161 + 948714960400 = 1352631^2 + 974020^2 .

It is not a de Polignac number, because 2778325582561 - 2¹⁵ = 2778325549793 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2778325582561.

It is not an unprimeable number, because it can be changed into a prime (2778325582567) 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, 1768506906 + ... + 1768508476.

Almost surely, 2^{2778325582561} is an apocalyptic number.

2778325582561 is the 1666831-st square number.

2778325582561 is the 833416-th centered octagonal number.

It is an amenable number.

2778325582561 is a deficient number, since it is larger than the sum of its proper divisors (4392362418).

2778325582561 is an frugal number, since it uses more digits than its factorization.

2778325582561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5264 (or 2632 counting only the distinct ones).

The product of its digits is 56448000, while the sum is 61.

The spelling of 2778325582561 in words is "two trillion, seven hundred seventy-eight billion, three hundred twenty-five million, five hundred eighty-two thousand, five hundred sixty-one".