1278550345 has 4 divisors (see below), whose sum is σ = 1534260420. Its totient is φ = 1022840272.

The previous prime is 1278550327. The next prime is 1278550379. The reversal of 1278550345 is 5430558721.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 864183609 + 414366736 = 29397^2 + 20356^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1278550345 is a prime.

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 junction number, because it is equal to n+sod(n) for n = 1278550298 and 1278550307.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 127855030 + ... + 127855039.

It is an arithmetic number, because the mean of its divisors is an integer number (383565105).

Almost surely, 2^1278550345 is an apocalyptic number.

It is an amenable number.

1278550345 is a deficient number, since it is larger than the sum of its proper divisors (255710075).

1278550345 is an equidigital number, since it uses as much as digits as its factorization.

1278550345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255710074.

The product of its (nonzero) digits is 168000, while the sum is 40.

The square root of 1278550345 is about 35756.8223560204. The cubic root of 1278550345 is about 1085.3569991887.

The spelling of 1278550345 in words is "one billion, two hundred seventy-eight million, five hundred fifty thousand, three hundred forty-five".