81342993 has 4 divisors (see below), whose sum is σ = 108457328. Its totient is φ = 54228660.

The previous prime is 81342991. The next prime is 81343021. The reversal of 81342993 is 39924318.

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 81342993 - 2¹ = 81342991 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81342991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13557163 + ... + 13557168.

It is an arithmetic number, because the mean of its divisors is an integer number (27114332).

Almost surely, 2^81342993 is an apocalyptic number.

It is an amenable number.

81342993 is a deficient number, since it is larger than the sum of its proper divisors (27114335).

81342993 is a wasteful number, since it uses less digits than its factorization.

81342993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27114334.

The product of its digits is 46656, while the sum is 39.

The square root of 81342993 is about 9019.0350370758. The cubic root of 81342993 is about 433.2847289996.

The spelling of 81342993 in words is "eighty-one million, three hundred forty-two thousand, nine hundred ninety-three".