1305128657 has 8 divisors (see below), whose sum is σ = 1519718976. Its totient is φ = 1097574192.

The previous prime is 1305128653. The next prime is 1305128659. The reversal of 1305128657 is 7568215031.

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 1305128657 - 2² = 1305128653 is a prime.

It is a super-2 number, since 2×1305128657² = 3406721622645247298, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1305128657.

It is not an unprimeable number, because it can be changed into a prime (1305128651) 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, 1758563 + ... + 1759304.

It is an arithmetic number, because the mean of its divisors is an integer number (189964872).

Almost surely, 2^1305128657 is an apocalyptic number.

It is an amenable number.

1305128657 is a deficient number, since it is larger than the sum of its proper divisors (214590319).

1305128657 is an equidigital number, since it uses as much as digits as its factorization.

1305128657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3517927.

The product of its (nonzero) digits is 50400, while the sum is 38.

The square root of 1305128657 is about 36126.5644228731. The cubic root of 1305128657 is about 1092.8262253843.

The spelling of 1305128657 in words is "one billion, three hundred five million, one hundred twenty-eight thousand, six hundred fifty-seven".