128555290 has 8 divisors (see below), whose sum is σ = 231399540. Its totient is φ = 51422112.

The previous prime is 128555281. The next prime is 128555327. The reversal of 128555290 is 92555821.

It can be written as a sum of positive squares in 2 ways, for example, as 118613881 + 9941409 = 10891^2 + 3153^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6427755 + ... + 6427774.

Almost surely, 2^128555290 is an apocalyptic number.

128555290 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

128555290 is a deficient number, since it is larger than the sum of its proper divisors (102844250).

128555290 is a wasteful number, since it uses less digits than its factorization.

128555290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12855536.

The product of its (nonzero) digits is 36000, while the sum is 37.

The square root of 128555290 is about 11338.2225238350. Note that the first 3 decimals coincide. The cubic root of 128555290 is about 504.6961410943.

It can be divided in two parts, 12855 and 5290, that added together give a triangular number (18145 = T₁₉₀).

The spelling of 128555290 in words is "one hundred twenty-eight million, five hundred fifty-five thousand, two hundred ninety".