1604412778 has 4 divisors (see below), whose sum is σ = 2406619170. Its totient is φ = 802206388.

The previous prime is 1604412751. The next prime is 1604412787. The reversal of 1604412778 is 8772144061.

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., 1058396089 + 546016689 = 32533^2 + 23367^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 1604412778.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 401103193 + ... + 401103196.

Almost surely, 2^1604412778 is an apocalyptic number.

1604412778 is a deficient number, since it is larger than the sum of its proper divisors (802206392).

1604412778 is an equidigital number, since it uses as much as digits as its factorization.

1604412778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 802206391.

The product of its (nonzero) digits is 75264, while the sum is 40.

The square root of 1604412778 is about 40055.1217449155. The cubic root of 1604412778 is about 1170.6813617145.

The spelling of 1604412778 in words is "one billion, six hundred four million, four hundred twelve thousand, seven hundred seventy-eight".