65721055112257 has 4 divisors (see below), whose sum is σ = 67987298392020. Its totient is φ = 63454811832496.

The previous prime is 65721055112227. The next prime is 65721055112261. The reversal of 65721055112257 is 75221155012756.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 48909447873841 + 16811607238416 = 6993529^2 + 4100196^2 .

It is a cyclic number.

It is not a de Polignac number, because 65721055112257 - 2³⁵ = 65686695373889 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 65721055112257.

It is not an unprimeable number, because it can be changed into a prime (65721055112227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1133121639838 + ... + 1133121639895.

It is an arithmetic number, because the mean of its divisors is an integer number (16996824598005).

Almost surely, 2^{65721055112257} is an apocalyptic number.

It is an amenable number.

65721055112257 is a deficient number, since it is larger than the sum of its proper divisors (2266243279763).

65721055112257 is a wasteful number, since it uses less digits than its factorization.

65721055112257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2266243279762.

The product of its (nonzero) digits is 1470000, while the sum is 49.

The spelling of 65721055112257 in words is "sixty-five trillion, seven hundred twenty-one billion, fifty-five million, one hundred twelve thousand, two hundred fifty-seven".