81239903174 has 4 divisors (see below), whose sum is σ = 121859854764. Its totient is φ = 40619951586.

The previous prime is 81239903167. The next prime is 81239903191. The reversal of 81239903174 is 47130993218.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20309975792 + ... + 20309975795.

It is an arithmetic number, because the mean of its divisors is an integer number (30464963691).

Almost surely, 2^81239903174 is an apocalyptic number.

81239903174 is a deficient number, since it is larger than the sum of its proper divisors (40619951590).

81239903174 is a wasteful number, since it uses less digits than its factorization.

81239903174 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40619951589.

The product of its (nonzero) digits is 326592, while the sum is 47.

The spelling of 81239903174 in words is "eighty-one billion, two hundred thirty-nine million, nine hundred three thousand, one hundred seventy-four".