1255021553 has 4 divisors (see below), whose sum is σ = 1256005620. Its totient is φ = 1254037488.

The previous prime is 1255021451. The next prime is 1255021561. The reversal of 1255021553 is 3551205521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3551205521 = 3923 ⋅905227.

It can be written as a sum of positive squares in 2 ways, for example, as 886074289 + 368947264 = 29767^2 + 19208^2 .

It is a cyclic number.

It is not a de Polignac number, because 1255021553 - 2¹² = 1255017457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1255041553) 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 in 3 ways as a sum of consecutive naturals, for example, 490118 + ... + 492671.

It is an arithmetic number, because the mean of its divisors is an integer number (314001405).

Almost surely, 2^1255021553 is an apocalyptic number.

It is an amenable number.

1255021553 is a deficient number, since it is larger than the sum of its proper divisors (984067).

1255021553 is an equidigital number, since it uses as much as digits as its factorization.

1255021553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 984066.

The product of its (nonzero) digits is 7500, while the sum is 29.

The square root of 1255021553 is about 35426.2833641916. The cubic root of 1255021553 is about 1078.6578987808.

The spelling of 1255021553 in words is "one billion, two hundred fifty-five million, twenty-one thousand, five hundred fifty-three".