1275643634 has 4 divisors (see below), whose sum is σ = 1913465454. Its totient is φ = 637821816.

The previous prime is 1275643631. The next prime is 1275643639. The reversal of 1275643634 is 4363465721.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 4363465721 = 43 ⋅101475947.

It can be written as a sum of positive squares in only one way, i.e., 1267146409 + 8497225 = 35597^2 + 2915^2 .

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1275643591 and 1275643600.

It is not an unprimeable number, because it can be changed into a prime (1275643631) 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 as a sum of consecutive naturals, namely, 318910907 + ... + 318910910.

Almost surely, 2^1275643634 is an apocalyptic number.

1275643634 is a deficient number, since it is larger than the sum of its proper divisors (637821820).

1275643634 is an equidigital number, since it uses as much as digits as its factorization.

1275643634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 637821819.

The product of its digits is 362880, while the sum is 41.

The square root of 1275643634 is about 35716.1536842925. The cubic root of 1275643634 is about 1084.5338761020.

The spelling of 1275643634 in words is "one billion, two hundred seventy-five million, six hundred forty-three thousand, six hundred thirty-four".