99999999977 has 2 divisors, whose sum is σ = 99999999978. Its totient is φ = 99999999976.

The previous prime is 99999999947. The next prime is 100000000003. The reversal of 99999999977 is 77999999999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 99972321856 + 27678121 = 316184^2 + 5261^2 .

It is an emirp because it is prime and its reverse (77999999999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 99999999977 - 2¹² = 99999995881 is a prime.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 99999999977.

It is not a weakly prime, because it can be changed into another prime (99999999907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49999999988 + 49999999989.

It is an arithmetic number, because the mean of its divisors is an integer number (49999999989).

Almost surely, 2^99999999977 is an apocalyptic number.

It is an amenable number.

99999999977 is a deficient number, since it is larger than the sum of its proper divisors (1).

99999999977 is an equidigital number, since it uses as much as digits as its factorization.

99999999977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18983603961, while the sum is 95.

The spelling of 99999999977 in words is "ninety-nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred seventy-seven".