1275720491 has 2 divisors, whose sum is σ = 1275720492. Its totient is φ = 1275720490.

The previous prime is 1275720473. The next prime is 1275720493. The reversal of 1275720491 is 1940275721.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1275720491 - 2⁶ = 1275720427 is a prime.

Together with 1275720493, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1275720493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 637860245 + 637860246.

It is an arithmetic number, because the mean of its divisors is an integer number (637860246).

Almost surely, 2^1275720491 is an apocalyptic number.

1275720491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1275720491 is an equidigital number, since it uses as much as digits as its factorization.

1275720491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 35280, while the sum is 38.

The square root of 1275720491 is about 35717.2296098116. The cubic root of 1275720491 is about 1084.5556565700. Note that the first 3 decimals are identical.

The spelling of 1275720491 in words is "one billion, two hundred seventy-five million, seven hundred twenty thousand, four hundred ninety-one".