9891261551 has 8 divisors (see below), whose sum is σ = 9935735040. Its totient is φ = 9846868248.

The previous prime is 9891261529. The next prime is 9891261607. The reversal of 9891261551 is 1551621989.

It is a happy number.

9891261551 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9891261551 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 9891261496 and 9891261505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9891261451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 234410 + ... + 273368.

It is an arithmetic number, because the mean of its divisors is an integer number (1241966880).

Almost surely, 2^9891261551 is an apocalyptic number.

9891261551 is a deficient number, since it is larger than the sum of its proper divisors (44473489).

9891261551 is a wasteful number, since it uses less digits than its factorization.

9891261551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40093.

The product of its digits is 194400, while the sum is 47.

The square root of 9891261551 is about 99454.8216578764. The cubic root of 9891261551 is about 2146.5972169668.

The spelling of 9891261551 in words is "nine billion, eight hundred ninety-one million, two hundred sixty-one thousand, five hundred fifty-one".