55128731369 has 4 divisors (see below), whose sum is σ = 55286693700. Its totient is φ = 54970769040.

The previous prime is 55128731347. The next prime is 55128731377. The reversal of 55128731369 is 96313782155.

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 26038017769 + 29090713600 = 161363^2 + 170560^2 .

It is a cyclic number.

It is not a de Polignac number, because 55128731369 - 2²⁸ = 54860295913 is a prime.

It is a super-2 number, since 2×55128731369² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55128731309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 78980642 + ... + 78981339.

It is an arithmetic number, because the mean of its divisors is an integer number (13821673425).

Almost surely, 2^55128731369 is an apocalyptic number.

It is an amenable number.

55128731369 is a deficient number, since it is larger than the sum of its proper divisors (157962331).

55128731369 is a wasteful number, since it uses less digits than its factorization.

55128731369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157962330.

The product of its digits is 1360800, while the sum is 50.

The spelling of 55128731369 in words is "fifty-five billion, one hundred twenty-eight million, seven hundred thirty-one thousand, three hundred sixty-nine".