1272427657 has 4 divisors (see below), whose sum is σ = 1296435780. Its totient is φ = 1248419536.

The previous prime is 1272427627. The next prime is 1272427687. The reversal of 1272427657 is 7567242721.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (1272427627) and next prime (1272427687).

It can be written as a sum of positive squares in 2 ways, for example, as 347598736 + 924828921 = 18644^2 + 30411^2 .

It is a cyclic number.

It is not a de Polignac number, because 1272427657 - 2¹⁵ = 1272394889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1272427627) 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 3 ways as a sum of consecutive naturals, for example, 12003982 + ... + 12004087.

It is an arithmetic number, because the mean of its divisors is an integer number (324108945).

Almost surely, 2^1272427657 is an apocalyptic number.

It is an amenable number.

1272427657 is a deficient number, since it is larger than the sum of its proper divisors (24008123).

1272427657 is an equidigital number, since it uses as much as digits as its factorization.

1272427657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24008122.

The product of its digits is 329280, while the sum is 43.

The square root of 1272427657 is about 35671.1039498359. The cubic root of 1272427657 is about 1083.6217166667.

The spelling of 1272427657 in words is "one billion, two hundred seventy-two million, four hundred twenty-seven thousand, six hundred fifty-seven".