99881779 has 2 divisors, whose sum is σ = 99881780. Its totient is φ = 99881778.

The previous prime is 99881777. The next prime is 99881809. The reversal of 99881779 is 97718899.

It is a weak prime.

It is an emirp because it is prime and its reverse (97718899) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 99881779 - 2¹ = 99881777 is a prime.

Together with 99881777, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (99881777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49940889 + 49940890.

It is an arithmetic number, because the mean of its divisors is an integer number (49940890).

Almost surely, 2^99881779 is an apocalyptic number.

99881779 is a deficient number, since it is larger than the sum of its proper divisors (1).

99881779 is an equidigital number, since it uses as much as digits as its factorization.

99881779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2286144, while the sum is 58.

The square root of 99881779 is about 9994.0872019410. The cubic root of 99881779 is about 463.9759001430.

The spelling of 99881779 in words is "ninety-nine million, eight hundred eighty-one thousand, seven hundred seventy-nine".