128978 has 4 divisors (see below), whose sum is σ = 193470. Its totient is φ = 64488.

The previous prime is 128971. The next prime is 128981. The reversal of 128978 is 879821.

It is a happy number.

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., 104329 + 24649 = 323^2 + 157^2 .

It is not an unprimeable number, because it can be changed into a prime (128971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32243 + ... + 32246.

2¹²⁸⁹⁷⁸ is an apocalyptic number.

128978 is a deficient number, since it is larger than the sum of its proper divisors (64492).

128978 is an equidigital number, since it uses as much as digits as its factorization.

128978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64491.

The product of its digits is 8064, while the sum is 35.

The square root of 128978 is about 359.1350720829. The cubic root of 128978 is about 50.5248709306.

The spelling of 128978 in words is "one hundred twenty-eight thousand, nine hundred seventy-eight".