9918719971 has 2 divisors, whose sum is σ = 9918719972. Its totient is φ = 9918719970.

The previous prime is 9918719963. The next prime is 9918720017. The reversal of 9918719971 is 1799178199.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9918719971 - 2³ = 9918719963 is a prime.

It is a super-2 number, since 2×9918719971² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (9918719911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4959359985 + 4959359986.

It is an arithmetic number, because the mean of its divisors is an integer number (4959359986).

Almost surely, 2^9918719971 is an apocalyptic number.

9918719971 is a deficient number, since it is larger than the sum of its proper divisors (1).

9918719971 is an equidigital number, since it uses as much as digits as its factorization.

9918719971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2571912, while the sum is 61.

The square root of 9918719971 is about 99592.7706763900. The cubic root of 9918719971 is about 2148.5817198167.

The spelling of 9918719971 in words is "nine billion, nine hundred eighteen million, seven hundred nineteen thousand, nine hundred seventy-one".