65720006663761 has 4 divisors (see below), whose sum is σ = 65720389522612. Its totient is φ = 65719623804912.

The previous prime is 65720006663723. The next prime is 65720006663767. The reversal of 65720006663761 is 16736660002756.

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 35936955625536 + 29783051038225 = 5994744^2 + 5457385^2 .

It is a cyclic number.

It is not a de Polignac number, because 65720006663761 - 2²³ = 65719998275153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65720006663767) 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, 191171826 + ... + 191515291.

It is an arithmetic number, because the mean of its divisors is an integer number (16430097380653).

Almost surely, 2^{65720006663761} is an apocalyptic number.

It is an amenable number.

65720006663761 is a deficient number, since it is larger than the sum of its proper divisors (382858851).

65720006663761 is a wasteful number, since it uses less digits than its factorization.

65720006663761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 382858850.

The product of its (nonzero) digits is 11430720, while the sum is 55.

The spelling of 65720006663761 in words is "sixty-five trillion, seven hundred twenty billion, six million, six hundred sixty-three thousand, seven hundred sixty-one".