81800675 has 12 divisors (see below), whose sum is σ = 110654376. Its totient is φ = 59491200.

The previous prime is 81800671. The next prime is 81800683. The reversal of 81800675 is 57600818.

It is a happy number.

It is not a de Polignac number, because 81800675 - 2² = 81800671 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81800671) by changing a digit.

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, 148454 + ... + 149003.

It is an arithmetic number, because the mean of its divisors is an integer number (9221198).

Almost surely, 2^81800675 is an apocalyptic number.

81800675 is a deficient number, since it is larger than the sum of its proper divisors (28853701).

81800675 is a wasteful number, since it uses less digits than its factorization.

81800675 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297478 (or 297473 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 35.

The square root of 81800675 is about 9044.3725597744. The cubic root of 81800675 is about 434.0958451701.

The spelling of 81800675 in words is "eighty-one million, eight hundred thousand, six hundred seventy-five".