128398646 has 4 divisors (see below), whose sum is σ = 192597972. Its totient is φ = 64199322.

The previous prime is 128398639. The next prime is 128398663. The reversal of 128398646 is 646893821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 646893821 = 7 ⋅92413403.

It is a self number, because there is not a number n which added to its sum of digits gives 128398646.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32099660 + ... + 32099663.

It is an arithmetic number, because the mean of its divisors is an integer number (48149493).

Almost surely, 2^128398646 is an apocalyptic number.

128398646 is a deficient number, since it is larger than the sum of its proper divisors (64199326).

128398646 is an equidigital number, since it uses as much as digits as its factorization.

128398646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64199325.

The product of its digits is 497664, while the sum is 47.

The square root of 128398646 is about 11331.3126335831. The cubic root of 128398646 is about 504.4910678414.

The spelling of 128398646 in words is "one hundred twenty-eight million, three hundred ninety-eight thousand, six hundred forty-six".