9891297025 has 9 divisors (see below), whose sum is σ = 12265824963. Its totient is φ = 7912639800.

The previous prime is 9891296981. The next prime is 9891297047. The reversal of 9891297025 is 5207921989.

The square root of 9891297025 is 99455.

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., 3560866929 + 6330430096 = 59673^2 + 79564^2 .

It is not a de Polignac number, because 9891297025 - 2⁷ = 9891296897 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 487330 + ... + 507220.

Almost surely, 2^9891297025 is an apocalyptic number.

9891297025 is the 99455-th square number.

9891297025 is the 49728-th centered octagonal number.

It is an amenable number.

9891297025 is a deficient number, since it is larger than the sum of its proper divisors (2374527938).

9891297025 is an frugal number, since it uses more digits than its factorization.

9891297025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39792 (or 19896 counting only the distinct ones).

The product of its (nonzero) digits is 816480, while the sum is 52.

The cubic root of 9891297025 is about 2146.5997831477.

It can be divided in two parts, 9891 and 297025, that added together give a square (306916 = 554²).

The spelling of 9891297025 in words is "nine billion, eight hundred ninety-one million, two hundred ninety-seven thousand, twenty-five".