1243264378 has 4 divisors (see below), whose sum is σ = 1864896570. Its totient is φ = 621632188.

The previous prime is 1243264357. The next prime is 1243264381. The reversal of 1243264378 is 8734623421.

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., 986399649 + 256864729 = 31407^2 + 16027^2 .

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 1243264378.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310816093 + ... + 310816096.

Almost surely, 2^1243264378 is an apocalyptic number.

1243264378 is a deficient number, since it is larger than the sum of its proper divisors (621632192).

1243264378 is an equidigital number, since it uses as much as digits as its factorization.

1243264378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 621632191.

The product of its digits is 193536, while the sum is 40.

The square root of 1243264378 is about 35259.9543108042. The cubic root of 1243264378 is about 1075.2789982172.

Adding to 1243264378 its reverse (8734623421), we get a palindrome (9977887799).

The spelling of 1243264378 in words is "one billion, two hundred forty-three million, two hundred sixty-four thousand, three hundred seventy-eight".