1278778054 has 4 divisors (see below), whose sum is σ = 1918167084. Its totient is φ = 639389026.

The previous prime is 1278778051. The next prime is 1278778057. The reversal of 1278778054 is 4508778721.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 4508778721 = 3391 ⋅1329631.

It is an interprime number because it is at equal distance from previous prime (1278778051) and next prime (1278778057).

It is a super-2 number, since 2×1278778054² = 3270546622784053832, which contains 22 as substring.

It is a Smith number, since the sum of its digits (49) 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 = 1278777989 and 1278778007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278778051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319694512 + ... + 319694515.

It is an arithmetic number, because the mean of its divisors is an integer number (479541771).

Almost surely, 2^1278778054 is an apocalyptic number.

1278778054 is a deficient number, since it is larger than the sum of its proper divisors (639389030).

1278778054 is an equidigital number, since it uses as much as digits as its factorization.

1278778054 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 639389029.

The product of its (nonzero) digits is 878080, while the sum is 49.

The square root of 1278778054 is about 35760.0063478742. The cubic root of 1278778054 is about 1085.4214291601.

The spelling of 1278778054 in words is "one billion, two hundred seventy-eight million, seven hundred seventy-eight thousand, fifty-four".