81959750 has 16 divisors (see below), whose sum is σ = 153429120. Its totient is φ = 32783800.

The previous prime is 81959743. The next prime is 81959777. The reversal of 81959750 is 5795918.

It is a happy number.

It is a Curzon number.

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 7 ways as a sum of consecutive naturals, for example, 163670 + ... + 164169.

It is an arithmetic number, because the mean of its divisors is an integer number (9589320).

Almost surely, 2^81959750 is an apocalyptic number.

81959750 is a deficient number, since it is larger than the sum of its proper divisors (71469370).

81959750 is a wasteful number, since it uses less digits than its factorization.

81959750 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327856 (or 327846 counting only the distinct ones).

The product of its (nonzero) digits is 113400, while the sum is 44.

The square root of 81959750 is about 9053.1624308857. The cubic root of 81959750 is about 434.3770534554.

The spelling of 81959750 in words is "eighty-one million, nine hundred fifty-nine thousand, seven hundred fifty".