1255540421 has 2 divisors, whose sum is σ = 1255540422. Its totient is φ = 1255540420.

The previous prime is 1255540409. The next prime is 1255540427. The reversal of 1255540421 is 1240455521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1140750625 + 114789796 = 33775^2 + 10714^2 .

It is a cyclic number.

It is not a de Polignac number, because 1255540421 - 2¹⁴ = 1255524037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1255540427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 627770210 + 627770211.

It is an arithmetic number, because the mean of its divisors is an integer number (627770211).

Almost surely, 2^1255540421 is an apocalyptic number.

It is an amenable number.

1255540421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1255540421 is an equidigital number, since it uses as much as digits as its factorization.

1255540421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8000, while the sum is 29.

The square root of 1255540421 is about 35433.6058142549. The cubic root of 1255540421 is about 1078.8065294166.

Adding to 1255540421 its reverse (1240455521), we get a palindrome (2495995942).

The spelling of 1255540421 in words is "one billion, two hundred fifty-five million, five hundred forty thousand, four hundred twenty-one".