99181939 has 2 divisors, whose sum is σ = 99181940. Its totient is φ = 99181938.

The previous prime is 99181937. The next prime is 99181963. The reversal of 99181939 is 93918199.

99181939 = T₈₁₃₀ + T₈₁₃₁ + T₈₁₃₂.

It is a weak prime.

It is an emirp because it is prime and its reverse (93918199) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 99181939 - 2¹ = 99181937 is a prime.

Together with 99181937, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 99181892 and 99181901.

It is not a weakly prime, because it can be changed into another prime (99181937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49590969 + 49590970.

It is an arithmetic number, because the mean of its divisors is an integer number (49590970).

Almost surely, 2^99181939 is an apocalyptic number.

99181939 is the 8132-nd centered triangular number.

99181939 is a deficient number, since it is larger than the sum of its proper divisors (1).

99181939 is an equidigital number, since it uses as much as digits as its factorization.

99181939 is an evil number, because the sum of its binary digits is even.

The product of its digits is 157464, while the sum is 49.

The square root of 99181939 is about 9959.0129530993. The cubic root of 99181939 is about 462.8897152532.

The spelling of 99181939 in words is "ninety-nine million, one hundred eighty-one thousand, nine hundred thirty-nine".