91198317147961 has 9 divisors (see below), whose sum is σ = 91406181435181. Its totient is φ = 90990924553984.

The previous prime is 91198317147869. The next prime is 91198317148031. The reversal of 91198317147961 is 16974171389119.

The square root of 91198317147961 is 9549781.

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 3513446587561 + 87684870560400 = 1874419^2 + 9364020^2 .

It is not a de Polignac number, because 91198317147961 - 2⁹ = 91198317147449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91198317147361) 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, 4287841035 + ... + 4287862303.

Almost surely, 2^{91198317147961} is an apocalyptic number.

91198317147961 is the 9549781-st square number.

91198317147961 is the 4774891-st centered octagonal number.

It is an amenable number.

91198317147961 is a deficient number, since it is larger than the sum of its proper divisors (207864287220).

91198317147961 is an frugal number, since it uses more digits than its factorization.

91198317147961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43436 (or 21718 counting only the distinct ones).

The product of its digits is 20575296, while the sum is 67.

The spelling of 91198317147961 in words is "ninety-one trillion, one hundred ninety-eight billion, three hundred seventeen million, one hundred forty-seven thousand, nine hundred sixty-one".