1275821971 has 2 divisors, whose sum is σ = 1275821972. Its totient is φ = 1275821970.

The previous prime is 1275821929. The next prime is 1275821977. The reversal of 1275821971 is 1791285721.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1275821971 is a prime.

It is not a weakly prime, because it can be changed into another prime (1275821977) 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 as a sum of consecutive naturals, namely, 637910985 + 637910986.

It is an arithmetic number, because the mean of its divisors is an integer number (637910986).

Almost surely, 2^1275821971 is an apocalyptic number.

1275821971 is a deficient number, since it is larger than the sum of its proper divisors (1).

1275821971 is an equidigital number, since it uses as much as digits as its factorization.

1275821971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 70560, while the sum is 43.

The square root of 1275821971 is about 35718.6501844625. The cubic root of 1275821971 is about 1084.5844135981.

The spelling of 1275821971 in words is "one billion, two hundred seventy-five million, eight hundred twenty-one thousand, nine hundred seventy-one".