99999971 has 2 divisors, whose sum is σ = 99999972. Its totient is φ = 99999970.

The previous prime is 99999959. The next prime is 99999989. The reversal of 99999971 is 17999999.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 99999971 - 2²² = 95805667 is a prime.

It is a Chen prime.

It is a nialpdrome in base 10.

It is not a weakly prime, because it can be changed into another prime (99999931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49999985 + 49999986.

It is an arithmetic number, because the mean of its divisors is an integer number (49999986).

Almost surely, 2^99999971 is an apocalyptic number.

99999971 is a deficient number, since it is larger than the sum of its proper divisors (1).

99999971 is an equidigital number, since it uses as much as digits as its factorization.

99999971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3720087, while the sum is 62.

The square root of 99999971 is about 9999.9985499999. The cubic root of 99999971 is about 464.1588384926.

The spelling of 99999971 in words is "ninety-nine million, nine hundred ninety-nine thousand, nine hundred seventy-one".