128305978 has 4 divisors (see below), whose sum is σ = 192458970. Its totient is φ = 64152988.

The previous prime is 128305927. The next prime is 128305979. The reversal of 128305978 is 879503821.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 127080529 + 1225449 = 11273^2 + 1107^2 .

It is not an unprimeable number, because it can be changed into a prime (128305979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32076493 + ... + 32076496.

Almost surely, 2^128305978 is an apocalyptic number.

128305978 is a deficient number, since it is larger than the sum of its proper divisors (64152992).

128305978 is an equidigital number, since it uses as much as digits as its factorization.

128305978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64152991.

The product of its (nonzero) digits is 120960, while the sum is 43.

The square root of 128305978 is about 11327.2228723549. Note that the first 3 decimals coincide. The cubic root of 128305978 is about 504.3696713648.

The spelling of 128305978 in words is "one hundred twenty-eight million, three hundred five thousand, nine hundred seventy-eight".