9691671791025 has 135 divisors (see below), whose sum is σ = 20885431692411. Its totient is φ = 4430030240160.

The previous prime is 9691671791017. The next prime is 9691671791051. The reversal of 9691671791025 is 5201971761969.

The square root of 9691671791025 is 3113145.

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

It can be written as a sum of positive squares in only one way, i.e., 3489001844769 + 6202669946256 = 1867887^2 + 2490516^2 .

It is a tau number, because it is divible by the number of its divisors (135).

It is not a de Polignac number, because 9691671791025 - 2³ = 9691671791017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 980635734 + ... + 980645616.

Almost surely, 2^{9691671791025} is an apocalyptic number.

9691671791025 is the 3113145-th square number.

9691671791025 is the 1556573-rd centered octagonal number.

It is an amenable number.

9691671791025 is an abundant number, since it is smaller than the sum of its proper divisors (11193759901386).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9691671791025 is an frugal number, since it uses more digits than its factorization.

9691671791025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19802 (or 9898 counting only the distinct ones).

The product of its (nonzero) digits is 12859560, while the sum is 63.

The spelling of 9691671791025 in words is "nine trillion, six hundred ninety-one billion, six hundred seventy-one million, seven hundred ninety-one thousand, twenty-five".