971591362561 has 4 divisors (see below), whose sum is σ = 981211079124. Its totient is φ = 961971646000.

The previous prime is 971591362549. The next prime is 971591362571. The reversal of 971591362561 is 165263195179.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 775923148225 + 195668214336 = 880865^2 + 442344^2 .

It is a cyclic number.

It is not a de Polignac number, because 971591362561 - 2¹⁷ = 971591231489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (971591362531) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4809858130 + ... + 4809858331.

It is an arithmetic number, because the mean of its divisors is an integer number (245302769781).

Almost surely, 2^971591362561 is an apocalyptic number.

It is an amenable number.

971591362561 is a deficient number, since it is larger than the sum of its proper divisors (9619716563).

971591362561 is a wasteful number, since it uses less digits than its factorization.

971591362561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9619716562.

The product of its digits is 3061800, while the sum is 55.

The spelling of 971591362561 in words is "nine hundred seventy-one billion, five hundred ninety-one million, three hundred sixty-two thousand, five hundred sixty-one".