128209278478 has 32 divisors (see below), whose sum is σ = 205530796800. Its totient is φ = 59804796096.

The previous prime is 128209278433. The next prime is 128209278529. The reversal of 128209278478 is 874872902821.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1747743 + ... + 1819621.

It is an arithmetic number, because the mean of its divisors is an integer number (6422837400).

Almost surely, 2^128209278478 is an apocalyptic number.

128209278478 is a deficient number, since it is larger than the sum of its proper divisors (77321518322).

128209278478 is a wasteful number, since it uses less digits than its factorization.

128209278478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72616.

The product of its (nonzero) digits is 7225344, while the sum is 58.

The spelling of 128209278478 in words is "one hundred twenty-eight billion, two hundred nine million, two hundred seventy-eight thousand, four hundred seventy-eight".