53378681665 has 16 divisors (see below), whose sum is σ = 65678371920. Its totient is φ = 41622266880.

The previous prime is 53378681663. The next prime is 53378681669. The reversal of 53378681665 is 56618687335.

It can be written as a sum of positive squares in 8 ways, for example, as 11984337729 + 41394343936 = 109473^2 + 203456^2 .

It is not a de Polignac number, because 53378681665 - 2¹ = 53378681663 is a prime.

It is not an unprimeable number, because it can be changed into a prime (53378681663) 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 15 ways as a sum of consecutive naturals, for example, 97357 + ... + 340933.

It is an arithmetic number, because the mean of its divisors is an integer number (4104898245).

Almost surely, 2^53378681665 is an apocalyptic number.

It is an amenable number.

53378681665 is a deficient number, since it is larger than the sum of its proper divisors (12299690255).

53378681665 is a wasteful number, since it uses less digits than its factorization.

53378681665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244692.

The product of its digits is 21772800, while the sum is 58.

The spelling of 53378681665 in words is "fifty-three billion, three hundred seventy-eight million, six hundred eighty-one thousand, six hundred sixty-five".