1328557978 has 24 divisors (see below), whose sum is σ = 2213094996. Its totient is φ = 597653760.

The previous prime is 1328557921. The next prime is 1328557987. The reversal of 1328557978 is 8797558231.

It can be written as a sum of positive squares in 2 ways, for example, as 1296216009 + 32341969 = 36003^2 + 5687^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4825 + ... + 51772.

Almost surely, 2^1328557978 is an apocalyptic number.

1328557978 is a deficient number, since it is larger than the sum of its proper divisors (884537018).

1328557978 is a wasteful number, since it uses less digits than its factorization.

1328557978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56718 (or 56707 counting only the distinct ones).

The product of its digits is 4233600, while the sum is 55.

The square root of 1328557978 is about 36449.3892678602. The cubic root of 1328557978 is about 1099.3268548194.

The spelling of 1328557978 in words is "one billion, three hundred twenty-eight million, five hundred fifty-seven thousand, nine hundred seventy-eight".