1247713657 has 8 divisors (see below), whose sum is σ = 1322198856. Its totient is φ = 1173349632.

The previous prime is 1247713639. The next prime is 1247713673. The reversal of 1247713657 is 7563177421.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 460574521 + 787139136 = 21461^2 + 28056^2 .

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 1247713657 - 2²³ = 1239325049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1247713627) 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, 8638 + ... + 50695.

It is an arithmetic number, because the mean of its divisors is an integer number (165274857).

Almost surely, 2^1247713657 is an apocalyptic number.

1247713657 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

1247713657 is a deficient number, since it is larger than the sum of its proper divisors (74485199).

1247713657 is a wasteful number, since it uses less digits than its factorization.

1247713657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60587.

The product of its digits is 246960, while the sum is 43.

The square root of 1247713657 is about 35322.9904877829. The cubic root of 1247713657 is about 1076.5601739583.

The spelling of 1247713657 in words is "one billion, two hundred forty-seven million, seven hundred thirteen thousand, six hundred fifty-seven".