1256473609 has 4 divisors (see below), whose sum is σ = 1270591380. Its totient is φ = 1242355840.

The previous prime is 1256473573. The next prime is 1256473613. The reversal of 1256473609 is 9063746521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9063746521 = 62207 ⋅145703.

It can be written as a sum of positive squares in 2 ways, for example, as 375274384 + 881199225 = 19372^2 + 29685^2 .

It is a cyclic number.

It is not a de Polignac number, because 1256473609 - 2⁷ = 1256473481 is a prime.

It is a super-2 number, since 2×1256473609² = 3157451860226969762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1256473109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7058752 + ... + 7058929.

It is an arithmetic number, because the mean of its divisors is an integer number (317647845).

Almost surely, 2^1256473609 is an apocalyptic number.

It is an amenable number.

1256473609 is a deficient number, since it is larger than the sum of its proper divisors (14117771).

1256473609 is an equidigital number, since it uses as much as digits as its factorization.

1256473609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14117770.

The product of its (nonzero) digits is 272160, while the sum is 43.

The square root of 1256473609 is about 35446.7714890933. The cubic root of 1256473609 is about 1079.0737397149.

The spelling of 1256473609 in words is "one billion, two hundred fifty-six million, four hundred seventy-three thousand, six hundred nine".