99612181 has 2 divisors, whose sum is σ = 99612182. Its totient is φ = 99612180.

The previous prime is 99612179. The next prime is 99612211. The reversal of 99612181 is 18121699.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99500625 + 111556 = 9975^2 + 334^2 .

It is a cyclic number.

It is not a de Polignac number, because 99612181 - 2¹ = 99612179 is a prime.

It is a super-2 number, since 2×99612181² = 19845173207153522, which contains 22 as substring.

Together with 99612179, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 99612181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99612151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49806090 + 49806091.

It is an arithmetic number, because the mean of its divisors is an integer number (49806091).

Almost surely, 2^99612181 is an apocalyptic number.

It is an amenable number.

99612181 is a deficient number, since it is larger than the sum of its proper divisors (1).

99612181 is an equidigital number, since it uses as much as digits as its factorization.

99612181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 37.

The square root of 99612181 is about 9980.5902130084. The cubic root of 99612181 is about 463.5580738929.

The spelling of 99612181 in words is "ninety-nine million, six hundred twelve thousand, one hundred eighty-one".