1253278075421 has 2 divisors, whose sum is σ = 1253278075422. Its totient is φ = 1253278075420.

The previous prime is 1253278075339. The next prime is 1253278075463. The reversal of 1253278075421 is 1245708723521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 660245628025 + 593032447396 = 812555^2 + 770086^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1253278075421 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1253278075321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 626639037710 + 626639037711.

It is an arithmetic number, because the mean of its divisors is an integer number (626639037711).

Almost surely, 2^{1253278075421} is an apocalyptic number.

It is an amenable number.

1253278075421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1253278075421 is an equidigital number, since it uses as much as digits as its factorization.

1253278075421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 940800, while the sum is 47.

The spelling of 1253278075421 in words is "one trillion, two hundred fifty-three billion, two hundred seventy-eight million, seventy-five thousand, four hundred twenty-one".