81230899 has 4 divisors (see below), whose sum is σ = 82959264. Its totient is φ = 79502536.

The previous prime is 81230893. The next prime is 81230921. The reversal of 81230899 is 99803218.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99803218 = 2 ⋅49901609.

It is a cyclic number.

It is not a de Polignac number, because 81230899 - 2¹⁷ = 81099827 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81230893) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 864112 + ... + 864205.

It is an arithmetic number, because the mean of its divisors is an integer number (20739816).

Almost surely, 2^81230899 is an apocalyptic number.

81230899 is a deficient number, since it is larger than the sum of its proper divisors (1728365).

81230899 is a wasteful number, since it uses less digits than its factorization.

81230899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1728364.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 81230899 is about 9012.8185935367. The cubic root of 81230899 is about 433.0856094296.

The spelling of 81230899 in words is "eighty-one million, two hundred thirty thousand, eight hundred ninety-nine".