81689150 has 24 divisors (see below), whose sum is σ = 153371880. Its totient is φ = 32368160.

The previous prime is 81689129. The next prime is 81689171. The reversal of 81689150 is 5198618.

It is an interprime number because it is at equal distance from previous prime (81689129) and next prime (81689171).

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

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, 2285 + ... + 12984.

It is an arithmetic number, because the mean of its divisors is an integer number (6390495).

Almost surely, 2^81689150 is an apocalyptic number.

81689150 is a deficient number, since it is larger than the sum of its proper divisors (71682730).

81689150 is a wasteful number, since it uses less digits than its factorization.

81689150 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15388 (or 15383 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 38.

The square root of 81689150 is about 9038.2050209098. The cubic root of 81689150 is about 433.8984769646.

The spelling of 81689150 in words is "eighty-one million, six hundred eighty-nine thousand, one hundred fifty".