81989794 has 8 divisors (see below), whose sum is σ = 123076800. Its totient is φ = 40964196.

The previous prime is 81989771. The next prime is 81989801. The reversal of 81989794 is 49798918.

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, 11854 + ... + 17449.

It is an arithmetic number, because the mean of its divisors is an integer number (15384600).

Almost surely, 2^81989794 is an apocalyptic number.

81989794 is a deficient number, since it is larger than the sum of its proper divisors (41087006).

81989794 is a wasteful number, since it uses less digits than its factorization.

81989794 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30704.

The product of its digits is 1306368, while the sum is 55.

The square root of 81989794 is about 9054.8215885240. The cubic root of 81989794 is about 434.4301235290.

The spelling of 81989794 in words is "eighty-one million, nine hundred eighty-nine thousand, seven hundred ninety-four".