81820102 has 24 divisors (see below), whose sum is σ = 153752256. Its totient is φ = 32367888.

The previous prime is 81820073. The next prime is 81820117. The reversal of 81820102 is 20102818.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30838 + ... + 33385.

It is an arithmetic number, because the mean of its divisors is an integer number (6406344).

Almost surely, 2^81820102 is an apocalyptic number.

81820102 is a deficient number, since it is larger than the sum of its proper divisors (71932154).

81820102 is a wasteful number, since it uses less digits than its factorization.

81820102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64252 (or 64245 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 22.

The square root of 81820102 is about 9045.4464787538. The cubic root of 81820102 is about 434.1302072030.

The spelling of 81820102 in words is "eighty-one million, eight hundred twenty thousand, one hundred two".