81123394 has 8 divisors (see below), whose sum is σ = 132747408. Its totient is φ = 36874260.

The previous prime is 81123299. The next prime is 81123401. The reversal of 81123394 is 49332118.

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

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, 1843692 + ... + 1843735.

It is an arithmetic number, because the mean of its divisors is an integer number (16593426).

Almost surely, 2^81123394 is an apocalyptic number.

81123394 is a deficient number, since it is larger than the sum of its proper divisors (51624014).

81123394 is a wasteful number, since it uses less digits than its factorization.

81123394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3687440.

The product of its digits is 5184, while the sum is 31.

The square root of 81123394 is about 9006.8526134272. The cubic root of 81123394 is about 432.8944694259.

The spelling of 81123394 in words is "eighty-one million, one hundred twenty-three thousand, three hundred ninety-four".