9891261497 has 4 divisors (see below), whose sum is σ = 10652127780. Its totient is φ = 9130395216.

The previous prime is 9891261473. The next prime is 9891261529. The reversal of 9891261497 is 7941621989.

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 1043225401 + 8848036096 = 32299^2 + 94064^2 .

It is a cyclic number.

It is not a de Polignac number, because 9891261497 - 2¹² = 9891257401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9891261407) 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, 380433122 + ... + 380433147.

It is an arithmetic number, because the mean of its divisors is an integer number (2663031945).

Almost surely, 2^9891261497 is an apocalyptic number.

It is an amenable number.

9891261497 is a deficient number, since it is larger than the sum of its proper divisors (760866283).

9891261497 is a wasteful number, since it uses less digits than its factorization.

9891261497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 760866282.

The product of its digits is 1959552, while the sum is 56.

The square root of 9891261497 is about 99454.8213863963. The cubic root of 9891261497 is about 2146.5972130604.

The spelling of 9891261497 in words is "nine billion, eight hundred ninety-one million, two hundred sixty-one thousand, four hundred ninety-seven".