9171720861 has 8 divisors (see below), whose sum is σ = 12459696480. Its totient is φ = 5999112912.

The previous prime is 9171720851. The next prime is 9171720889. The reversal of 9171720861 is 1680271719.

9171720861 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 de Polignac number, because none of the positive numbers 2^k-9171720861 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9171720821) 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, 28841731 + ... + 28842048.

It is an arithmetic number, because the mean of its divisors is an integer number (1557462060).

Almost surely, 2^9171720861 is an apocalyptic number.

It is an amenable number.

9171720861 is a deficient number, since it is larger than the sum of its proper divisors (3287975619).

9171720861 is a wasteful number, since it uses less digits than its factorization.

9171720861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57683835.

The product of its (nonzero) digits is 42336, while the sum is 42.

The square root of 9171720861 is about 95769.1018074201. The cubic root of 9171720861 is about 2093.2299637895.

The spelling of 9171720861 in words is "nine billion, one hundred seventy-one million, seven hundred twenty thousand, eight hundred sixty-one".