128611369 has 4 divisors (see below), whose sum is σ = 128690644. Its totient is φ = 128532096.

The previous prime is 128611349. The next prime is 128611393. The reversal of 128611369 is 963116821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 963116821 = 19 ⋅50690359.

It can be written as a sum of positive squares in 2 ways, for example, as 61042969 + 67568400 = 7813^2 + 8220^2 .

It is a cyclic number.

It is not a de Polignac number, because 128611369 - 2⁹ = 128610857 is a prime.

It is a super-2 number, since 2×128611369² = 33081768472108322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128611339) 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, 37152 + ... + 40465.

It is an arithmetic number, because the mean of its divisors is an integer number (32172661).

Almost surely, 2^128611369 is an apocalyptic number.

It is an amenable number.

128611369 is a deficient number, since it is larger than the sum of its proper divisors (79275).

128611369 is an equidigital number, since it uses as much as digits as its factorization.

128611369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79274.

The product of its digits is 15552, while the sum is 37.

The square root of 128611369 is about 11340.6952608736. The cubic root of 128611369 is about 504.7695174095.

The spelling of 128611369 in words is "one hundred twenty-eight million, six hundred eleven thousand, three hundred sixty-nine".