128605837 has 4 divisors (see below), whose sum is σ = 129070396. Its totient is φ = 128141280.

The previous prime is 128605831. The next prime is 128605861. The reversal of 128605837 is 738506821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 738506821 = 13 ⋅56808217.

It can be written as a sum of positive squares in 2 ways, for example, as 10361961 + 118243876 = 3219^2 + 10874^2 .

It is a cyclic number.

It is not a de Polignac number, because 128605837 - 2⁷ = 128605709 is a prime.

It is a super-3 number, since 3×128605837³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128605837.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128605831) 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, 231864 + ... + 232417.

It is an arithmetic number, because the mean of its divisors is an integer number (32267599).

Almost surely, 2^128605837 is an apocalyptic number.

It is an amenable number.

128605837 is a deficient number, since it is larger than the sum of its proper divisors (464559).

128605837 is an equidigital number, since it uses as much as digits as its factorization.

128605837 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 464558.

The product of its (nonzero) digits is 80640, while the sum is 40.

The square root of 128605837 is about 11340.4513578605. The cubic root of 128605837 is about 504.7622800374.

The spelling of 128605837 in words is "one hundred twenty-eight million, six hundred five thousand, eight hundred thirty-seven".