99777971 has 2 divisors, whose sum is σ = 99777972. Its totient is φ = 99777970.

The previous prime is 99777967. The next prime is 99778013. The reversal of 99777971 is 17977799.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 99777971 - 2² = 99777967 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (99777901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49888985 + 49888986.

It is an arithmetic number, because the mean of its divisors is an integer number (49888986).

Almost surely, 2^99777971 is an apocalyptic number.

99777971 is a deficient number, since it is larger than the sum of its proper divisors (1).

99777971 is an equidigital number, since it uses as much as digits as its factorization.

99777971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1750329, while the sum is 56.

The square root of 99777971 is about 9988.8923810401. The cubic root of 99777971 is about 463.8151063650.

The spelling of 99777971 in words is "ninety-nine million, seven hundred seventy-seven thousand, nine hundred seventy-one".