61728399382717 has 2 divisors, whose sum is σ = 61728399382718. Its totient is φ = 61728399382716.

The previous prime is 61728399382711. The next prime is 61728399382739. The reversal of 61728399382717 is 71728399382716.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36916633720836 + 24811765661881 = 6075906^2 + 4981141^2 .

It is a cyclic number.

It is not a de Polignac number, because 61728399382717 - 2³⁹ = 61178643568829 is a prime.

It is a pancake number, because a pancake can be divided into 61728399382717 parts by 11111111 straight cuts.

It is a self number, because there is not a number n which added to its sum of digits gives 61728399382717.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61728399382711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30864199691358 + 30864199691359.

It is an arithmetic number, because the mean of its divisors is an integer number (30864199691359).

Almost surely, 2^{61728399382717} is an apocalyptic number.

It is an amenable number.

61728399382717 is a deficient number, since it is larger than the sum of its proper divisors (1).

61728399382717 is an equidigital number, since it uses as much as digits as its factorization.

61728399382717 is an evil number, because the sum of its binary digits is even.

The product of its digits is 384072192, while the sum is 73.

Subtracting 61728399382717 from its reverse (71728399382716), we obtain a palindrome (9999999999999).

It can be divided in two parts, 617283 and 99382717, that added together give a 8-th power (100000000 = 10⁸).

The spelling of 61728399382717 in words is "sixty-one trillion, seven hundred twenty-eight billion, three hundred ninety-nine million, three hundred eighty-two thousand, seven hundred seventeen".