1278721473 has 8 divisors (see below), whose sum is σ = 1724119200. Its totient is φ = 842902368.

The previous prime is 1278721469. The next prime is 1278721519. The reversal of 1278721473 is 3741278721.

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

It is not a de Polignac number, because 1278721473 - 2² = 1278721469 is a prime.

It is a super-2 number, since 2×1278721473² = 3270257211022579458, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1278721373) 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, 2394343 + ... + 2394876.

It is an arithmetic number, because the mean of its divisors is an integer number (215514900).

Almost surely, 2^1278721473 is an apocalyptic number.

It is an amenable number.

1278721473 is a deficient number, since it is larger than the sum of its proper divisors (445397727).

1278721473 is an equidigital number, since it uses as much as digits as its factorization.

1278721473 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4789311.

The product of its digits is 131712, while the sum is 42.

The square root of 1278721473 is about 35759.2152178987. The cubic root of 1278721473 is about 1085.4054203524.

The spelling of 1278721473 in words is "one billion, two hundred seventy-eight million, seven hundred twenty-one thousand, four hundred seventy-three".