1278474661 has 8 divisors (see below), whose sum is σ = 1303630848. Its totient is φ = 1253454000.

The previous prime is 1278474629. The next prime is 1278474709. The reversal of 1278474661 is 1664748721.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1278474661 - 2⁵ = 1278474629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278474161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14725 + ... + 52666.

It is an arithmetic number, because the mean of its divisors is an integer number (162953856).

Almost surely, 2^1278474661 is an apocalyptic number.

It is an amenable number.

1278474661 is a deficient number, since it is larger than the sum of its proper divisors (25156187).

1278474661 is an equidigital number, since it uses as much as digits as its factorization.

1278474661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67763.

The product of its digits is 451584, while the sum is 46.

The square root of 1278474661 is about 35755.7640248394. The cubic root of 1278474661 is about 1085.3355828035.

The spelling of 1278474661 in words is "one billion, two hundred seventy-eight million, four hundred seventy-four thousand, six hundred sixty-one".