65721710 has 16 divisors (see below), whose sum is σ = 119472192. Its totient is φ = 26028000.

The previous prime is 65721709. The next prime is 65721713. The reversal of 65721710 is 1712756.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65721713) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 31526 + ... + 33545.

It is an arithmetic number, because the mean of its divisors is an integer number (7467012).

Almost surely, 2^65721710 is an apocalyptic number.

65721710 is a deficient number, since it is larger than the sum of its proper divisors (53750482).

65721710 is a wasteful number, since it uses less digits than its factorization.

65721710 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65179.

The product of its (nonzero) digits is 2940, while the sum is 29.

The square root of 65721710 is about 8106.8927462993. The cubic root of 65721710 is about 403.5552035364. Note that the first 3 decimals are identical.

The spelling of 65721710 in words is "sixty-five million, seven hundred twenty-one thousand, seven hundred ten".