1255407821 has 2 divisors, whose sum is σ = 1255407822. Its totient is φ = 1255407820.

The previous prime is 1255407779. The next prime is 1255407859. The reversal of 1255407821 is 1287045521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1079845321 + 175562500 = 32861^2 + 13250^2 .

It is a cyclic number.

It is not a de Polignac number, because 1255407821 - 2¹⁴ = 1255391437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1255307821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 627703910 + 627703911.

It is an arithmetic number, because the mean of its divisors is an integer number (627703911).

Almost surely, 2^1255407821 is an apocalyptic number.

It is an amenable number.

1255407821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1255407821 is an equidigital number, since it uses as much as digits as its factorization.

1255407821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22400, while the sum is 35.

The square root of 1255407821 is about 35431.7346597651. The cubic root of 1255407821 is about 1078.7685498131.

The spelling of 1255407821 in words is "one billion, two hundred fifty-five million, four hundred seven thousand, eight hundred twenty-one".