1263828644 has 24 divisors (see below), whose sum is σ = 2395941240. Its totient is φ = 583301472.

The previous prime is 1263828641. The next prime is 1263828667. The reversal of 1263828644 is 4468283621.

It can be written as a sum of positive squares in 4 ways, for example, as 286015744 + 977812900 = 16912^2 + 31270^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1263828595 and 1263828604.

It is not an unprimeable number, because it can be changed into a prime (1263828641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63119 + ... + 80694.

It is an arithmetic number, because the mean of its divisors is an integer number (99830885).

Almost surely, 2^1263828644 is an apocalyptic number.

It is an amenable number.

1263828644 is a deficient number, since it is larger than the sum of its proper divisors (1132112596).

1263828644 is a wasteful number, since it uses less digits than its factorization.

1263828644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143856 (or 143828 counting only the distinct ones).

The product of its digits is 442368, while the sum is 44.

The square root of 1263828644 is about 35550.3677055526. The cubic root of 1263828644 is about 1081.1751737052.

The spelling of 1263828644 in words is "one billion, two hundred sixty-three million, eight hundred twenty-eight thousand, six hundred forty-four".