99778841 has 2 divisors, whose sum is σ = 99778842. Its totient is φ = 99778840.

The previous prime is 99778829. The next prime is 99778867. The reversal of 99778841 is 14887799.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76930441 + 22848400 = 8771^2 + 4780^2 .

It is a cyclic number.

It is not a de Polignac number, because 99778841 - 2²² = 95584537 is a prime.

It is a super-2 number, since 2×99778841² = 19911634222606562, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (99778541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49889420 + 49889421.

It is an arithmetic number, because the mean of its divisors is an integer number (49889421).

Almost surely, 2^99778841 is an apocalyptic number.

It is an amenable number.

99778841 is a deficient number, since it is larger than the sum of its proper divisors (1).

99778841 is an equidigital number, since it uses as much as digits as its factorization.

99778841 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1016064, while the sum is 53.

The square root of 99778841 is about 9988.9359293170. The cubic root of 99778841 is about 463.8164544180.

The spelling of 99778841 in words is "ninety-nine million, seven hundred seventy-eight thousand, eight hundred forty-one".