1275112721 has 2 divisors, whose sum is σ = 1275112722. Its totient is φ = 1275112720.

The previous prime is 1275112613. The next prime is 1275112733. The reversal of 1275112721 is 1272115721.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 847450321 + 427662400 = 29111^2 + 20680^2 .

It is a cyclic number.

It is not a de Polignac number, because 1275112721 - 2¹⁴ = 1275096337 is a prime.

It is not a weakly prime, because it can be changed into another prime (1275112121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 637556360 + 637556361.

It is an arithmetic number, because the mean of its divisors is an integer number (637556361).

Almost surely, 2^1275112721 is an apocalyptic number.

It is an amenable number.

1275112721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1275112721 is an equidigital number, since it uses as much as digits as its factorization.

1275112721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1960, while the sum is 29.

The square root of 1275112721 is about 35708.7205175431. The cubic root of 1275112721 is about 1084.3833970243.

The spelling of 1275112721 in words is "one billion, two hundred seventy-five million, one hundred twelve thousand, seven hundred twenty-one".