210128409 has 12 divisors (see below), whose sum is σ = 304080816. Its totient is φ = 139826232.

The previous prime is 210128357. The next prime is 210128417. The reversal of 210128409 is 904821012.

It is not a de Polignac number, because 210128409 - 2⁸ = 210128153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (210128489) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16419 + ... + 26264.

It is an arithmetic number, because the mean of its divisors is an integer number (25340068).

Almost surely, 2^210128409 is an apocalyptic number.

It is an amenable number.

210128409 is a deficient number, since it is larger than the sum of its proper divisors (93952407).

210128409 is a wasteful number, since it uses less digits than its factorization.

210128409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43236 (or 43233 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 210128409 is about 14495.8066005311. The cubic root of 210128409 is about 594.5133218728.

The spelling of 210128409 in words is "two hundred ten million, one hundred twenty-eight thousand, four hundred nine".