1278481167218 has 4 divisors (see below), whose sum is σ = 1917721750830. Its totient is φ = 639240583608.

The previous prime is 1278481167209. The next prime is 1278481167263. The reversal of 1278481167218 is 8127611848721.

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., 869606605729 + 408874561489 = 932527^2 + 639433^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319620291803 + ... + 319620291806.

Almost surely, 2^{1278481167218} is an apocalyptic number.

1278481167218 is a deficient number, since it is larger than the sum of its proper divisors (639240583612).

1278481167218 is an equidigital number, since it uses as much as digits as its factorization.

1278481167218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 639240583611.

The product of its digits is 2408448, while the sum is 56.

The spelling of 1278481167218 in words is "one trillion, two hundred seventy-eight billion, four hundred eighty-one million, one hundred sixty-seven thousand, two hundred eighteen".