81997803 has 12 divisors (see below), whose sum is σ = 119197728. Its totient is φ = 54316080.

The previous prime is 81997789. The next prime is 81997823. The reversal of 81997803 is 30879918.

It is not a de Polignac number, because 81997803 - 2¹⁶ = 81932267 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81997823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27603 + ... + 30428.

It is an arithmetic number, because the mean of its divisors is an integer number (9933144).

Almost surely, 2^81997803 is an apocalyptic number.

81997803 is a deficient number, since it is larger than the sum of its proper divisors (37199925).

81997803 is a wasteful number, since it uses less digits than its factorization.

81997803 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58194 (or 58191 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 45.

The square root of 81997803 is about 9055.2638282935. The cubic root of 81997803 is about 434.4442685317. Note that the first 3 decimals are identical.

The spelling of 81997803 in words is "eighty-one million, nine hundred ninety-seven thousand, eight hundred three".