81039023 has 4 divisors (see below), whose sum is σ = 87272808. Its totient is φ = 74805240.

The previous prime is 81039019. The next prime is 81039041. The reversal of 81039023 is 32093018.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32093018 = 2 ⋅16046509.

It is a cyclic number.

It is not a de Polignac number, because 81039023 - 2² = 81039019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81038983 and 81039001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81039043) 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, 3116873 + ... + 3116898.

It is an arithmetic number, because the mean of its divisors is an integer number (21818202).

Almost surely, 2^81039023 is an apocalyptic number.

81039023 is a deficient number, since it is larger than the sum of its proper divisors (6233785).

81039023 is a wasteful number, since it uses less digits than its factorization.

81039023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6233784.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 81039023 is about 9002.1676833971. The cubic root of 81039023 is about 432.7443425358.

The spelling of 81039023 in words is "eighty-one million, thirty-nine thousand, twenty-three".