1778806370961 has 63 divisors (see below), whose sum is σ = 2727536491353. Its totient is φ = 1159535298600.

The previous prime is 1778806370947. The next prime is 1778806370969. The reversal of 1778806370961 is 1690736088771.

The square root of 1778806370961 is 1333719.

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

1778806370961 is a `hidden beast` number, since 177 + 8 + 8 + 0 + 6 + 370 + 96 + 1 = 666.

It is not a de Polignac number, because 1778806370961 - 2⁹ = 1778806370449 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1778806370969) by changing a digit.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 1692488886 + ... + 1692489936.

Almost surely, 2^{1778806370961} is an apocalyptic number.

1778806370961 is the 1333719-th square number.

1778806370961 is the 666860-th centered octagonal number.

It is an amenable number.

1778806370961 is a deficient number, since it is larger than the sum of its proper divisors (948730120392).

1778806370961 is an frugal number, since it uses more digits than its factorization.

1778806370961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2214 (or 1101 counting only the distinct ones).

The product of its (nonzero) digits is 21337344, while the sum is 63.

The spelling of 1778806370961 in words is "one trillion, seven hundred seventy-eight billion, eight hundred six million, three hundred seventy thousand, nine hundred sixty-one".