291747978769 has 9 divisors (see below), whose sum is σ = 315924054033. Its totient is φ = 269299344912.

The previous prime is 291747978727. The next prime is 291747978881. The reversal of 291747978769 is 967879747192.

The square root of 291747978769 is 540137.

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 203486699025 + 88261279744 = 451095^2 + 297088^2 .

It is not a de Polignac number, because 291747978769 - 2¹¹ = 291747976721 is a prime.

It is a super-2 number, since 2×291747978769² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 291747978695 and 291747978704.

It is not an unprimeable number, because it can be changed into a prime (291747970769) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 7001007 + ... + 7042555.

Almost surely, 2^291747978769 is an apocalyptic number.

291747978769 is the 540137-th square number.

291747978769 is the 270069-th centered octagonal number.

It is an amenable number.

291747978769 is a deficient number, since it is larger than the sum of its proper divisors (24176075264).

291747978769 is an frugal number, since it uses more digits than its factorization.

291747978769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83124 (or 41562 counting only the distinct ones).

The product of its digits is 672126336, while the sum is 76.

The spelling of 291747978769 in words is "two hundred ninety-one billion, seven hundred forty-seven million, nine hundred seventy-eight thousand, seven hundred sixty-nine".