128185261 has 8 divisors (see below), whose sum is σ = 129685248. Its totient is φ = 126690000.

The previous prime is 128185237. The next prime is 128185297. The reversal of 128185261 is 162581821.

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

It is a cyclic number.

It is not a de Polignac number, because 128185261 - 2¹³ = 128177069 is a prime.

It is a super-2 number, since 2×128185261² = 32862922275276242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128185201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 103516 + ... + 104746.

It is an arithmetic number, because the mean of its divisors is an integer number (16210656).

Almost surely, 2^128185261 is an apocalyptic number.

It is an amenable number.

128185261 is a deficient number, since it is larger than the sum of its proper divisors (1499987).

128185261 is a wasteful number, since it uses less digits than its factorization.

128185261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2363.

The product of its digits is 7680, while the sum is 34.

The square root of 128185261 is about 11321.8929954315. The cubic root of 128185261 is about 504.2114425759.

The spelling of 128185261 in words is "one hundred twenty-eight million, one hundred eighty-five thousand, two hundred sixty-one".