9771920947 has 2 divisors, whose sum is σ = 9771920948. Its totient is φ = 9771920946.

The previous prime is 9771920911. The next prime is 9771920971. The reversal of 9771920947 is 7490291779.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 9771920947 - 2¹⁵ = 9771888179 is a prime.

It is not a weakly prime, because it can be changed into another prime (9771921947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4885960473 + 4885960474.

It is an arithmetic number, because the mean of its divisors is an integer number (4885960474).

Almost surely, 2^9771920947 is an apocalyptic number.

9771920947 is a deficient number, since it is larger than the sum of its proper divisors (1).

9771920947 is an equidigital number, since it uses as much as digits as its factorization.

9771920947 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2000376, while the sum is 55.

The square root of 9771920947 is about 98853.0269996827. The cubic root of 9771920947 is about 2137.9291804988.

The spelling of 9771920947 in words is "nine billion, seven hundred seventy-one million, nine hundred twenty thousand, nine hundred forty-seven".