81847798 has 4 divisors (see below), whose sum is σ = 122771700. Its totient is φ = 40923898.

The previous prime is 81847793. The next prime is 81847859. The reversal of 81847798 is 89774818.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81847793) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20461948 + ... + 20461951.

It is an arithmetic number, because the mean of its divisors is an integer number (30692925).

Almost surely, 2^81847798 is an apocalyptic number.

81847798 is a deficient number, since it is larger than the sum of its proper divisors (40923902).

81847798 is a wasteful number, since it uses less digits than its factorization.

81847798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40923901.

The product of its digits is 903168, while the sum is 52.

The square root of 81847798 is about 9046.9772852594. The cubic root of 81847798 is about 434.1791858505.

The spelling of 81847798 in words is "eighty-one million, eight hundred forty-seven thousand, seven hundred ninety-eight".