81387710 has 16 divisors (see below), whose sum is σ = 151224192. Its totient is φ = 31504800.

The previous prime is 81387703. The next prime is 81387737. The reversal of 81387710 is 1778318.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 130961 + ... + 131580.

It is an arithmetic number, because the mean of its divisors is an integer number (9451512).

Almost surely, 2^81387710 is an apocalyptic number.

81387710 is a deficient number, since it is larger than the sum of its proper divisors (69836482).

81387710 is a wasteful number, since it uses less digits than its factorization.

81387710 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262579.

The product of its (nonzero) digits is 9408, while the sum is 35.

The square root of 81387710 is about 9021.5137310764. The cubic root of 81387710 is about 433.3641115548.

The spelling of 81387710 in words is "eighty-one million, three hundred eighty-seven thousand, seven hundred ten".