81800150 has 36 divisors (see below), whose sum is σ = 154763532. Its totient is φ = 32166720.

The previous prime is 81800119. The next prime is 81800221. The reversal of 81800150 is 5100818.

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 17 ways as a sum of consecutive naturals, for example, 266297 + ... + 266603.

It is an arithmetic number, because the mean of its divisors is an integer number (4298987).

Almost surely, 2^81800150 is an apocalyptic number.

81800150 is a deficient number, since it is larger than the sum of its proper divisors (72963382).

81800150 is a wasteful number, since it uses less digits than its factorization.

81800150 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 465 (or 387 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 23.

The square root of 81800150 is about 9044.3435361556. The cubic root of 81800150 is about 434.0949164866.

Adding to 81800150 its reverse (5100818), we get a palindrome (86900968).

The spelling of 81800150 in words is "eighty-one million, eight hundred thousand, one hundred fifty".