99813281 has 2 divisors, whose sum is σ = 99813282. Its totient is φ = 99813280.

The previous prime is 99813253. The next prime is 99813293. The reversal of 99813281 is 18231899.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 92948881 + 6864400 = 9641^2 + 2620^2 .

It is a cyclic number.

It is not a de Polignac number, because 99813281 - 2¹⁴ = 99796897 is a prime.

It is a super-2 number, since 2×99813281² = 19925382127969922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (99815281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49906640 + 49906641.

It is an arithmetic number, because the mean of its divisors is an integer number (49906641).

Almost surely, 2^99813281 is an apocalyptic number.

It is an amenable number.

99813281 is a deficient number, since it is larger than the sum of its proper divisors (1).

99813281 is an equidigital number, since it uses as much as digits as its factorization.

99813281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 41.

The square root of 99813281 is about 9990.6596879285. The cubic root of 99813281 is about 463.8698124280.

The spelling of 99813281 in words is "ninety-nine million, eight hundred thirteen thousand, two hundred eighty-one".