81371750 has 16 divisors (see below), whose sum is σ = 152328384. Its totient is φ = 32548600.

The previous prime is 81371749. The next prime is 81371753. The reversal of 81371750 is 5717318.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81371753) 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 7 ways as a sum of consecutive naturals, for example, 162494 + ... + 162993.

It is an arithmetic number, because the mean of its divisors is an integer number (9520524).

Almost surely, 2^81371750 is an apocalyptic number.

81371750 is a deficient number, since it is larger than the sum of its proper divisors (70956634).

81371750 is a wasteful number, since it uses less digits than its factorization.

81371750 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325504 (or 325494 counting only the distinct ones).

The product of its (nonzero) digits is 5880, while the sum is 32.

The square root of 81371750 is about 9020.6291354872. The cubic root of 81371750 is about 433.3357823662.

The spelling of 81371750 in words is "eighty-one million, three hundred seventy-one thousand, seven hundred fifty".