1243781644 has 12 divisors (see below), whose sum is σ = 2487563344. Its totient is φ = 533049264.

The previous prime is 1243781593. The next prime is 1243781663. The reversal of 1243781644 is 4461873421.

1243781644 is an admirable number.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 1243781597 and 1243781606.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22210359 + ... + 22210414.

Almost surely, 2^1243781644 is an apocalyptic number.

1243781644 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1243781644 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

1243781644 is a wasteful number, since it uses less digits than its factorization.

1243781644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44420784 (or 44420782 counting only the distinct ones).

The product of its digits is 129024, while the sum is 40.

The square root of 1243781644 is about 35267.2885830482. The cubic root of 1243781644 is about 1075.4281025045.

The spelling of 1243781644 in words is "one billion, two hundred forty-three million, seven hundred eighty-one thousand, six hundred forty-four".