9172947871 has 2 divisors, whose sum is σ = 9172947872. Its totient is φ = 9172947870.

The previous prime is 9172947869. The next prime is 9172947877. The reversal of 9172947871 is 1787492719.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9172947871 - 2¹ = 9172947869 is a prime.

Together with 9172947869, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9172947877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4586473935 + 4586473936.

It is an arithmetic number, because the mean of its divisors is an integer number (4586473936).

Almost surely, 2^9172947871 is an apocalyptic number.

9172947871 is a deficient number, since it is larger than the sum of its proper divisors (1).

9172947871 is an equidigital number, since it uses as much as digits as its factorization.

9172947871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1778112, while the sum is 55.

The square root of 9172947871 is about 95775.5076781115. The cubic root of 9172947871 is about 2093.3233050359.

The spelling of 9172947871 in words is "nine billion, one hundred seventy-two million, nine hundred forty-seven thousand, eight hundred seventy-one".