291668979865761 has 45 divisors (see below), whose sum is σ = 462844404306691. Its totient is φ = 183006347848128.

The previous prime is 291668979865729. The next prime is 291668979865789. The reversal of 291668979865761 is 167568979866192.

It is a happy number.

The square root of 291668979865761 is 17078319.

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

291668979865761 is a `hidden beast` number, since 29 + 1 + 6 + 6 + 8 + 9 + 7 + 9 + 8 + 6 + 576 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 227077925501025 + 64591054364736 = 15069105^2 + 8036856^2 .

It is not a de Polignac number, because 291668979865761 - 2⁵ = 291668979865729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (291668979865721) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 2612926996 + ... + 2613038618.

Almost surely, 2^{291668979865761} is an apocalyptic number.

291668979865761 is the 17078319-th square number.

291668979865761 is the 8539160-th centered octagonal number.

It is an amenable number.

291668979865761 is a deficient number, since it is larger than the sum of its proper divisors (171175424440930).

291668979865761 is an frugal number, since it uses more digits than its factorization.

291668979865761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223292 (or 111643 counting only the distinct ones).

The product of its digits is 29628426240, while the sum is 90.

The spelling of 291668979865761 in words is "two hundred ninety-one trillion, six hundred sixty-eight billion, nine hundred seventy-nine million, eight hundred sixty-five thousand, seven hundred sixty-one".