99812891 has 2 divisors, whose sum is σ = 99812892. Its totient is φ = 99812890.

The previous prime is 99812879. The next prime is 99812927. The reversal of 99812891 is 19821899.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 99812891 - 2¹⁰ = 99811867 is a prime.

It is a super-2 number, since 2×99812891² = 19925226419555762, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (99812821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49906445 + 49906446.

It is an arithmetic number, because the mean of its divisors is an integer number (49906446).

Almost surely, 2^99812891 is an apocalyptic number.

99812891 is a deficient number, since it is larger than the sum of its proper divisors (1).

99812891 is an equidigital number, since it uses as much as digits as its factorization.

99812891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 93312, while the sum is 47.

The square root of 99812891 is about 9990.6401696788. The cubic root of 99812891 is about 463.8692082683.

The spelling of 99812891 in words is "ninety-nine million, eight hundred twelve thousand, eight hundred ninety-one".