1325999778 has 32 divisors (see below), whose sum is σ = 2859675840. Its totient is φ = 408522240.

The previous prime is 1325999771. The next prime is 1325999791. The reversal of 1325999778 is 8779995231.

It is a super-2 number, since 2×1325999778² = 3516550822512098568, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1325999771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 137175 + ... + 146522.

It is an arithmetic number, because the mean of its divisors is an integer number (89364870).

Almost surely, 2^1325999778 is an apocalyptic number.

1325999778 is an abundant number, since it is smaller than the sum of its proper divisors (1533676062).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1325999778 is a wasteful number, since it uses less digits than its factorization.

1325999778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283762.

The product of its digits is 8573040, while the sum is 60.

The square root of 1325999778 is about 36414.2798638117. The cubic root of 1325999778 is about 1098.6207998309.

The spelling of 1325999778 in words is "one billion, three hundred twenty-five million, nine hundred ninety-nine thousand, seven hundred seventy-eight".