128421873 has 12 divisors (see below), whose sum is σ = 185744208. Its totient is φ = 85501080.

The previous prime is 128421869. The next prime is 128421877. The reversal of 128421873 is 378124821.

It is an interprime number because it is at equal distance from previous prime (128421869) and next prime (128421877).

It is not a de Polignac number, because 128421873 - 2² = 128421869 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128421877) 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, 1983 + ... + 16148.

It is an arithmetic number, because the mean of its divisors is an integer number (15478684).

Almost surely, 2^128421873 is an apocalyptic number.

It is an amenable number.

128421873 is a deficient number, since it is larger than the sum of its proper divisors (57322335).

128421873 is a wasteful number, since it uses less digits than its factorization.

128421873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18924 (or 18921 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 128421873 is about 11332.3374905621. The cubic root of 128421873 is about 504.5214864060.

The spelling of 128421873 in words is "one hundred twenty-eight million, four hundred twenty-one thousand, eight hundred seventy-three".