81468993 has 4 divisors (see below), whose sum is σ = 108625328. Its totient is φ = 54312660.

The previous prime is 81468971. The next prime is 81469019. The reversal of 81468993 is 39986418.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 81468993 - 2⁶ = 81468929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81468293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13578163 + ... + 13578168.

It is an arithmetic number, because the mean of its divisors is an integer number (27156332).

Almost surely, 2^81468993 is an apocalyptic number.

It is an amenable number.

81468993 is a deficient number, since it is larger than the sum of its proper divisors (27156335).

81468993 is a wasteful number, since it uses less digits than its factorization.

81468993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27156334.

The product of its digits is 373248, while the sum is 48.

The square root of 81468993 is about 9026.0175603640. The cubic root of 81468993 is about 433.5083324082.

The spelling of 81468993 in words is "eighty-one million, four hundred sixty-eight thousand, nine hundred ninety-three".