1247439617 has 4 divisors (see below), whose sum is σ = 1320818436. Its totient is φ = 1174060800.

The previous prime is 1247439607. The next prime is 1247439649. The reversal of 1247439617 is 7169347421.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7169347421 = 139 ⋅51578039.

It can be written as a sum of positive squares in 2 ways, for example, as 512162161 + 735277456 = 22631^2 + 27116^2 .

It is not a de Polignac number, because 1247439617 - 2⁴ = 1247439601 is a prime.

It is a super-2 number, since 2×1247439617² = 3112211196122213378, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1247439607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36689384 + ... + 36689417.

It is an arithmetic number, because the mean of its divisors is an integer number (330204609).

Almost surely, 2^1247439617 is an apocalyptic number.

1247439617 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

1247439617 is a deficient number, since it is larger than the sum of its proper divisors (73378819).

1247439617 is an equidigital number, since it uses as much as digits as its factorization.

1247439617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73378818.

The product of its digits is 254016, while the sum is 44.

The square root of 1247439617 is about 35319.1112147517. Note that the first 3 decimals coincide. The cubic root of 1247439617 is about 1076.4813518798.

The spelling of 1247439617 in words is "one billion, two hundred forty-seven million, four hundred thirty-nine thousand, six hundred seventeen".