81223857238 has 8 divisors (see below), whose sum is σ = 121840168320. Its totient is φ = 40610467800.

The previous prime is 81223857229. The next prime is 81223857287. The reversal of 81223857238 is 83275832218.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 81223857191 and 81223857200.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 659533 + ... + 772936.

It is an arithmetic number, because the mean of its divisors is an integer number (15230021040).

Almost surely, 2^81223857238 is an apocalyptic number.

81223857238 is a deficient number, since it is larger than the sum of its proper divisors (40616311082).

81223857238 is a wasteful number, since it uses less digits than its factorization.

81223857238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1460822.

The product of its digits is 1290240, while the sum is 49.

The spelling of 81223857238 in words is "eighty-one billion, two hundred twenty-three million, eight hundred fifty-seven thousand, two hundred thirty-eight".