81500738 has 32 divisors (see below), whose sum is σ = 137979072. Its totient is φ = 35784000.

The previous prime is 81500729. The next prime is 81500761. The reversal of 81500738 is 83700518.

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 15 ways as a sum of consecutive naturals, for example, 95120 + ... + 95972.

It is an arithmetic number, because the mean of its divisors is an integer number (4311846).

Almost surely, 2^81500738 is an apocalyptic number.

81500738 is a deficient number, since it is larger than the sum of its proper divisors (56478334).

81500738 is a wasteful number, since it uses less digits than its factorization.

81500738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1010.

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 81500738 is about 9027.7759165810. The cubic root of 81500738 is about 433.5646316801.

The spelling of 81500738 in words is "eighty-one million, five hundred thousand, seven hundred thirty-eight".